Today we follow the Stockfish - Ethereal game in round 33. There were only 2 decisive games so far in RR5 out of 17 played. Can Stockfish break the sequence of draws? Can Ethereal hold? I'm not considering the option that Ethereal can win, too farfetched. Stockfish and Ethereal have played 4 games so far in the division, Stockfish won twice with white and once with black, only one draw so far.
move 12: We are in the Sicilian section of Cato's openings. The 8-move book has been played in recent games of high level. Stockfish's eval at the opening is less than 0.5, relatively drawish. So far the engines are following the most played line, Stockfish's eval is starting to increase, Ethereal is still confident it can hold.
move 16: Stockfish did not expect Ethereal's move 13, its eval dropped in response, then jumped back up in the next move. Ethereal's move 15 was again unexpected, this time Stockfish's eval jumped over 0.8. The black king side loks a little weak.
move 20: Ethereal's eval dropped to 0 for a moment, then came back. Ethereal now has a passer in the center, it is not going anywhere soon though. The center opened up a little, the black DS bishop looks bad now. Stockfish's eval jumped to around 1 on move 20, Ethereal's eval also jumped over 0.5, the evals are trending higher.
move 25: Both are expecting exchanges soon. Stockfish surprised Ethereal (and everyone else) with Kg1, Ethereal's eval jumped. Then Stockfish made its signature move g4, this time eval dropping, very unstable in this game so far. Stockfish is a pawn up after exchanging a pair of bishops and a pair of knights, evals starting to come down.
move 29: Evals dropping to 0, it seems Ethereal is holding after all. The engines are delaying the exchanges, both PVs look similar and drawish. This is going to be a draw, I'll come back later to verify.
move 58: As expected the game ended in a draw, though it took 30 more moves for the draw rule to kick in.
Friday, September 21, 2018
Thursday, September 20, 2018
Season 13 premier division after RR4
Crosstable after RR4
Stockfish maintained its 3.5 point lead at the top of the table. Houdini is in 2nd, extending its lead over Komodo to 1.5 points after beating it for the second time in the division. Chiron won its first game, it is still in the relegation zone together with Ginkgo. Andscacs and Ethereal are a point ahead, Fire is 2.5 points clear of Ethereal after Ethereal lost 3 games in RR4.
A few interesting games
Houdini - Chiron: Houdini's eval gradually increased after the opening. Houdini captured a pawn and created an advanced passer in the center. Chiron had to block the passer, defened its pieces and protect its king against a potential attack on the long diagonal. Chiron's defense collapsed after Houdini opened a file on the king side. Houdini reduced to a QRB vs QRN position and finished with a bishop sacrifice, leading to a won endgame.
Stockfish - Houdini: Stockfish was a rook for bishop up in a closed RN vs BN position, Houdini kept the pawn line strong and held the draw.
Ginkgo - Ethereal: For 50 moves evals were close to 0, then they suddenly jumped over 1. The engines exchanged most pieces and only RB vs RB remained and Ginkgo advanced a passer to the 7th rank. Ethereal was a pawn up but had to prevent Ginkgo from promoting the pawn, both engines couldn't improve and the game ended in a draw.
Houdini - Komodo: See featured game below. This was the second win for Houdini against Komodo in the division.
Houdini - Ginkgo: Houdini gave a rook for a bishop but had an advanced passer in the center. Ginkgo realized it was in trouble too late, its king was exposed and it had to block the passer. Ginkgo's defense collapsed and the game was adjudicated before Houdini won more material.
Komodo - Fire: Komodo had a space advantage and eval over 1, Fire seemed to be holding. The engines exchanged pieces until only N vs B remained, then Fire blundered and Komodo's eval jumped over 3. The winning sequence was not trivial and very long, probably based on the fact that the black bishop had no targets. Fire saw it was lost and the game ended without demonstrating exactly how Komodo can win.
Stockfish - Andscacs: There were many early exchanges and only RR vs RN remained on move 25. Andscacs was a pawn up and it had a pawn majority on the queen side, Stockfish had a pawn majority on the king side. Eventually Stockfish forced a rook exchange to stop a king side passer and the game reached a tablebase R vs N win for white. A double win for Stockfish in this opening
Chiron - Ethereal: Ethereal gave a pawn and tried to develop a king side attack, but nothing came out of it. The engines shuffled essentially until move 82 when Ethereal captured a pawn and gave a rook for a bishop. Evals jumped to around 2, Chiron hid its king behind a black pawn and started advancing its central passers. There was another long shuffle, then the engines reduced to a QR vs QB position and evals continued to increase. 30 moves later both engines were sure of Chiron's win, PVs showed different possible lines, both quite long. This was the first win for Chiron in the division.
Ethereal - Stockfish: Stockfish took over the game early, it attacked the king side through the half open g file. Ethereal's pieces were tied down to defend the king side and Stockfish switched to the queen side. It won a pawn and reduced to a RRB vs RRB position. Stockfish had an advanced passer in the center, the game was adjudicated before Ethereal lost material. Stockfish won both games in this opening.
Fire - Ginkgo: There were many early exchanges, only QBB vs QNN remained on move 30. Evals increased gradually, Fire exchanged a bishop for a knight and then managed to move its queen behind Ginkgo's pawns. The black king was exposed to attacks and Fire used this to reduce to a won queen ending.
Komodo - Ethereal: Komodo had space advantage on the king side, evals were close to 1 though it was a pawn down. The engines essentially shuffled until move 98, then finally Komodo started its king side attack, perhaps following a blunder by Ethereal. Komodo went up a rook for a bishop and opened the king side, then drove the black king to the center. Again the game ended long before the win was explicit.
Stockfish - Chiron: The engines castled in opposite directions, Stockfish pushed a pawn on the king side and weakened Chiron's king position. Evals increased quickly, the game reached a QN vs QB position where the black king was weak in the corner and the bishop had no pawn targets and couldn't support the black pawns. The game was quickly adjudicated. Stockfish won both sides of this opening.
Andscacs - Fire: Evals turned negative as Fire prepared a queen side attack in a closed position. However, when Fire opened the queen side evals dropped from 2 to 0. The game ended in a perpetual check.
Featured game: Houdini - Komodo
Premier division, round 24
Link to game on TCEC
The game started with evals close to 0. On move 15 Komodo allowed Houdini to block the center with a d5 pawn. Evals increased gradually as Houdini pushed pawns on the king side and had a space advantage. Komodo's pieces had less and less room to move.
Komodo tried to counter on the queen side and opened a file. Houdini blocked the file with an outpost knight on c6. Houdini continued to push its king side pawns, and when the pawn line reached g6 the black LS bishop was trapped.
Houdini concentrated its pieces on the queen side while threatening to open the king side with its pawns. Komodo had to keep an eye on both sides and its pieces were overextended. Eventually it allowed Houdini to advance a passer in the center, then gave a piece to stop it.
Houdini was up a piece and Komodo's king was trapped in the corner. This was enough for a win though the game ended before the win was evident.
Stockfish maintained its 3.5 point lead at the top of the table. Houdini is in 2nd, extending its lead over Komodo to 1.5 points after beating it for the second time in the division. Chiron won its first game, it is still in the relegation zone together with Ginkgo. Andscacs and Ethereal are a point ahead, Fire is 2.5 points clear of Ethereal after Ethereal lost 3 games in RR4.
A few interesting games
Houdini - Chiron: Houdini's eval gradually increased after the opening. Houdini captured a pawn and created an advanced passer in the center. Chiron had to block the passer, defened its pieces and protect its king against a potential attack on the long diagonal. Chiron's defense collapsed after Houdini opened a file on the king side. Houdini reduced to a QRB vs QRN position and finished with a bishop sacrifice, leading to a won endgame.
Stockfish - Houdini: Stockfish was a rook for bishop up in a closed RN vs BN position, Houdini kept the pawn line strong and held the draw.
Ginkgo - Ethereal: For 50 moves evals were close to 0, then they suddenly jumped over 1. The engines exchanged most pieces and only RB vs RB remained and Ginkgo advanced a passer to the 7th rank. Ethereal was a pawn up but had to prevent Ginkgo from promoting the pawn, both engines couldn't improve and the game ended in a draw.
Houdini - Komodo: See featured game below. This was the second win for Houdini against Komodo in the division.
Houdini - Ginkgo: Houdini gave a rook for a bishop but had an advanced passer in the center. Ginkgo realized it was in trouble too late, its king was exposed and it had to block the passer. Ginkgo's defense collapsed and the game was adjudicated before Houdini won more material.
Komodo - Fire: Komodo had a space advantage and eval over 1, Fire seemed to be holding. The engines exchanged pieces until only N vs B remained, then Fire blundered and Komodo's eval jumped over 3. The winning sequence was not trivial and very long, probably based on the fact that the black bishop had no targets. Fire saw it was lost and the game ended without demonstrating exactly how Komodo can win.
Stockfish - Andscacs: There were many early exchanges and only RR vs RN remained on move 25. Andscacs was a pawn up and it had a pawn majority on the queen side, Stockfish had a pawn majority on the king side. Eventually Stockfish forced a rook exchange to stop a king side passer and the game reached a tablebase R vs N win for white. A double win for Stockfish in this opening
Chiron - Ethereal: Ethereal gave a pawn and tried to develop a king side attack, but nothing came out of it. The engines shuffled essentially until move 82 when Ethereal captured a pawn and gave a rook for a bishop. Evals jumped to around 2, Chiron hid its king behind a black pawn and started advancing its central passers. There was another long shuffle, then the engines reduced to a QR vs QB position and evals continued to increase. 30 moves later both engines were sure of Chiron's win, PVs showed different possible lines, both quite long. This was the first win for Chiron in the division.
Ethereal - Stockfish: Stockfish took over the game early, it attacked the king side through the half open g file. Ethereal's pieces were tied down to defend the king side and Stockfish switched to the queen side. It won a pawn and reduced to a RRB vs RRB position. Stockfish had an advanced passer in the center, the game was adjudicated before Ethereal lost material. Stockfish won both games in this opening.
Fire - Ginkgo: There were many early exchanges, only QBB vs QNN remained on move 30. Evals increased gradually, Fire exchanged a bishop for a knight and then managed to move its queen behind Ginkgo's pawns. The black king was exposed to attacks and Fire used this to reduce to a won queen ending.
Komodo - Ethereal: Komodo had space advantage on the king side, evals were close to 1 though it was a pawn down. The engines essentially shuffled until move 98, then finally Komodo started its king side attack, perhaps following a blunder by Ethereal. Komodo went up a rook for a bishop and opened the king side, then drove the black king to the center. Again the game ended long before the win was explicit.
Stockfish - Chiron: The engines castled in opposite directions, Stockfish pushed a pawn on the king side and weakened Chiron's king position. Evals increased quickly, the game reached a QN vs QB position where the black king was weak in the corner and the bishop had no pawn targets and couldn't support the black pawns. The game was quickly adjudicated. Stockfish won both sides of this opening.
Andscacs - Fire: Evals turned negative as Fire prepared a queen side attack in a closed position. However, when Fire opened the queen side evals dropped from 2 to 0. The game ended in a perpetual check.
Featured game: Houdini - Komodo
Premier division, round 24
Link to game on TCEC
The game started with evals close to 0. On move 15 Komodo allowed Houdini to block the center with a d5 pawn. Evals increased gradually as Houdini pushed pawns on the king side and had a space advantage. Komodo's pieces had less and less room to move.
Komodo tried to counter on the queen side and opened a file. Houdini blocked the file with an outpost knight on c6. Houdini continued to push its king side pawns, and when the pawn line reached g6 the black LS bishop was trapped.
Houdini concentrated its pieces on the queen side while threatening to open the king side with its pawns. Komodo had to keep an eye on both sides and its pieces were overextended. Eventually it allowed Houdini to advance a passer in the center, then gave a piece to stop it.
Houdini was up a piece and Komodo's king was trapped in the corner. This was enough for a win though the game ended before the win was evident.
Sunday, September 16, 2018
Season 13 premier division after RR3
Crosstable after RR3
Stockfish is firmly in the lead after scoring 6/7 in RR3, including a second win against Komodo. Houdini drew all its games in RR3 but is still second, Komodo with 4/7 closed the gap to only 0.5 points. Ethereal lost once in RR3 and is now a point behind Fire in the race for 4th place. Chiron and Ginkgo close the table, Andscacs is a point clear of the relegation zone.
A few interesting games
Stockfish - Komodo: Komodo sacrificed a pawn on the queen side and attacked the white king side. The game reached a NN vs R imbalance, and Stockfish's eval started to increase. It advanced a queen side passer to the 6th rank. Komodo avoided exchanging queens for a while, when Stockfish forced the exchange only RBN vs RR remained and the game was adjudicated. A second win for Stockfish against Komodo in the division.
Ginkgo - Komodo: Ginkgo traded its queen for two rooks and the game reached a RRB vs QN position. Evals turned negative and gradually increased as Komodo outplayed Ginkgo. Komodo captured all the white pawns and was 3 pawns up when the game was adjudicated.
Houdini - Stockfish: Houdini was up a rook for a knight with an eval advantage, Stockfish reduced to a RR vs RN position and held the draw.
Andscacs - Stockfish: Evals turned negative over 1, Stockfish captured two pawns and created a queen side passer. Andscacs equalized material while evals continued to increase, after several exchanges only RB vs RN were left. Stockfish was two pawns up again and Andscacs' advanced passer was not strong enough. The game was adjudicated with Stockfish 4 pawns up.
Stockfish - Ethereal: The game reached a QRR vs QRR position with evals at 0. Evals started to increase on move 50, Stockfish calculated better than Ethereal. Stockfish opened the queen side and created a queen side passer. The combination of an advancing passer and threats on the exposed black king were enough for Stockfish to win. The game was over before Ethereal lost material.
Chiron - Stockfish: See featured game below.
Stockfish - Ginkgo: Evals were close to 0 for 35 moves in a closed position. Ginkgo's king was in the center uncastled, Stockfish gave a pawn and exchanged pieces, its eval jumped over 2.5. Then Stockfish created a king side passer in a QNN vs QBN position. After queens were exchanged Ginkgo was forced to lose a piece for the passer, leading to a won NN vs N endgame.
Komodo - Chiron: Komodo had an eval advantage of about 1 in a closed position. Chiron kept the evals under control for more than 40 moves. Komodo gave a pawn in a QRR vs QRR position and opened files, then Chiron blundered on move 46 and Komodo's eval jumped over 3. Komodo took over the 7th rank, exposing the black king to mate threats. It took a while for Chiron to realise it was losing.
Featured game: Chiron - Stockfish
Premier division, round 20
Link to game on TCEC
The engines castled in opposite directions, Stockfish pushed a pawn on the queen side and weakened the white king's defense. Then Stockfish sacrificed a pawn and a bishop and exposed the white king completely. Evals were negative though Chiron was a piece up.
King safety was a major concern for Chiron while Stockfish's king was safe in its corner. Stockfish drove the white king to the 7th rank and placed all its major pieces on the back rank. Analysis by Stockfish thought Chiron could still hold, until Chiron's 45th move.
Stockfish's eval jumped over 5, and Chiron's eval followed immediately. Stockfish pinned the white knight and together with mating threats and an advancing passer forced Chiron to trade a queen for a rook.
In the RRN vs QR position Chiron needed all its pieces to defend its king and Stockfish had time to capture the remaining white pawns on the king side before the game was adjudicated.
Stockfish is firmly in the lead after scoring 6/7 in RR3, including a second win against Komodo. Houdini drew all its games in RR3 but is still second, Komodo with 4/7 closed the gap to only 0.5 points. Ethereal lost once in RR3 and is now a point behind Fire in the race for 4th place. Chiron and Ginkgo close the table, Andscacs is a point clear of the relegation zone.
A few interesting games
Stockfish - Komodo: Komodo sacrificed a pawn on the queen side and attacked the white king side. The game reached a NN vs R imbalance, and Stockfish's eval started to increase. It advanced a queen side passer to the 6th rank. Komodo avoided exchanging queens for a while, when Stockfish forced the exchange only RBN vs RR remained and the game was adjudicated. A second win for Stockfish against Komodo in the division.
Ginkgo - Komodo: Ginkgo traded its queen for two rooks and the game reached a RRB vs QN position. Evals turned negative and gradually increased as Komodo outplayed Ginkgo. Komodo captured all the white pawns and was 3 pawns up when the game was adjudicated.
Houdini - Stockfish: Houdini was up a rook for a knight with an eval advantage, Stockfish reduced to a RR vs RN position and held the draw.
Andscacs - Stockfish: Evals turned negative over 1, Stockfish captured two pawns and created a queen side passer. Andscacs equalized material while evals continued to increase, after several exchanges only RB vs RN were left. Stockfish was two pawns up again and Andscacs' advanced passer was not strong enough. The game was adjudicated with Stockfish 4 pawns up.
Stockfish - Ethereal: The game reached a QRR vs QRR position with evals at 0. Evals started to increase on move 50, Stockfish calculated better than Ethereal. Stockfish opened the queen side and created a queen side passer. The combination of an advancing passer and threats on the exposed black king were enough for Stockfish to win. The game was over before Ethereal lost material.
Chiron - Stockfish: See featured game below.
Stockfish - Ginkgo: Evals were close to 0 for 35 moves in a closed position. Ginkgo's king was in the center uncastled, Stockfish gave a pawn and exchanged pieces, its eval jumped over 2.5. Then Stockfish created a king side passer in a QNN vs QBN position. After queens were exchanged Ginkgo was forced to lose a piece for the passer, leading to a won NN vs N endgame.
Komodo - Chiron: Komodo had an eval advantage of about 1 in a closed position. Chiron kept the evals under control for more than 40 moves. Komodo gave a pawn in a QRR vs QRR position and opened files, then Chiron blundered on move 46 and Komodo's eval jumped over 3. Komodo took over the 7th rank, exposing the black king to mate threats. It took a while for Chiron to realise it was losing.
Featured game: Chiron - Stockfish
Premier division, round 20
Link to game on TCEC
The engines castled in opposite directions, Stockfish pushed a pawn on the queen side and weakened the white king's defense. Then Stockfish sacrificed a pawn and a bishop and exposed the white king completely. Evals were negative though Chiron was a piece up.
King safety was a major concern for Chiron while Stockfish's king was safe in its corner. Stockfish drove the white king to the 7th rank and placed all its major pieces on the back rank. Analysis by Stockfish thought Chiron could still hold, until Chiron's 45th move.
Stockfish's eval jumped over 5, and Chiron's eval followed immediately. Stockfish pinned the white knight and together with mating threats and an advancing passer forced Chiron to trade a queen for a rook.
In the RRN vs QR position Chiron needed all its pieces to defend its king and Stockfish had time to capture the remaining white pawns on the king side before the game was adjudicated.
Thursday, September 13, 2018
Season 13 premier division after RR2
Crosstable after RR2
The reverse games have been played and the first double RR is over. Stockfish is in the lead with a +6 score. Houdini had 4 wins in RR2 including one against Komodo, it is in second place. Ginkgo and Chiron close the table with a -4 score, Andscacs is only 0.5 a point ahead in 6th place. Fire in 4th is 0.5 points ahead of Ethereal, each has one win in their head to head games.
A few interesting games
Fire - Ethereal: Fire had a space advantage with increasing evals. Fire created a queen side passer, and though its king was exposed it attacked on the king side. After exchanging most pieces the game reached a QB vs QN position. Fire grabbed two pawns and reduced to a winning endgame. Interesting to note that Ethereal saw it was losing a long time before Fire did. A biased opening with two white wins.
Houdini - Chiron: The engines castled in opposite directions. Houdini had a space advantage, after the king side pawns stabilized it focused on the queen side. Chiron did not have enough defenders and it lost a pawn. Houdini kept pressing, it won a second pawn, and the game was adjudicated in a Q vs RB imbalance. Houdini's first win in the division.
Komodo - Stockfish: Komodo had an eval around 1 for more than 50 moves, with a rook for knight advantage. Stockfish traded down to a RR vs RB position and held the draw.
Komodo - Ginkgo: The center was blocked and the engines castled in opposite directions. The king side had an open file that Ginkgo guarded with its rooks. Komodo's eval jumped and it exchanged a pair of rooks and created a king side passer. Then it captured a pawn on the queen side and penetrated with its queen. Ginkgo's defense collapsed and the game was adjudicated. Komodo had a double win in this opening.
Ethereal - Andscacs: The engines were essentially shufflling for a long time. Evals started to climb after Ethereal opened up the position. The game reached a RBB vs RBN position with Ethereal a pawn up. Ethereal went after the black pawns and the game was adjudicated when it was 3 pawns up. Another biased opening with two white wins.
Houdini - Komodo: See featured game below.
Houdini - Ginkgo: Houdini pushed pawns on the king side, and when the time was right it attacked the pawns defending the black king. Evals increased quickly, Houdini won a rook for a bishop and the game was adjudicated in a QRR vs QRB position. Two back to back wins for Houdini.
Stockfish - Andscacs: Andscacs gave a knight for 3 pawns, it forced Stockfish's king to walk to the king side uncastled. The game reached a RRB vs RR position with increasing evals. Stockfish outplayed Andscacs in the endgame. Its rooks attacked the black pawns and king while it kept one pawn safe, then reduced to a winning bishop ending. A double win for Stockfish in the opening.
Houdini - Andscacs: Houdini created a queen side passer, and although Andscacs fought hard to keep it from advancing ultimately Houdini used it to win the game. The game was adjudicated in a QRB vs QRB position with the passer on the 6th rank.
Komodo - Ethereal: The game reached a QRR vs QRB position with Ethereal two pawns up and evals around 1. Ethereal's pieces were passive and its bishop almost trapped behind the pawns. Komodo weakened the black king side and captured a pawn, the game was adjudicate before Ethereal lost more material.
Stockfish - Chiron: Stockfish had an eval of about 1, Chiron held the position for over 50 moves. The engines opened files on both sides, Stockfish walked its king to the queen side and then patiently applied pressure on Chiron. The game reached a QRN vs QRN position and Stockfish captured a pawn. When it captured a second pawn the game was adjudicated.
Ginkgo - Stockfish: The game reached a R vs BN imbalance with Ginkgo two pawns up. Evals were close to 0 until move 40, then started to increase in favor of Stockfish. There was a long shuffle and then Ginkgo gave a pawn and opened the king side with pawn moves. Despite a pair of connected passers in the center for white, Stockfish thought it was winning. It reduced to a RR vs RBN position and advanced a passer to the 2nd rank. Ginkgo had to give a rook for a knight to get rid of the passer, leading to a won RB vs R endgame for Stockfish.
Featured game: Houdini - Komodo
Premier division, round 10
Link to game on TCEC
Komodo gave a bishop for 3 pawns, creating two connected passers in the center. After exchanging queens Houdini had an eval advantage under 1 with a bishop pair, though the black pawns looked intimidating.
Houdini blocked the passers with its pieces, with evals increasing. After the engines stabilized the king side pawns evals were over 1.5, though it seemed that Komodo built a strong pawn line across the board.
Houdini doubled rooks on the e file and then broke through the center giving a rook for a knight. In the RBB vs RR position Houdini's bishops were very strong, Komodo's king was trapped in the corner.
Within a few moves the black king was in a mating net, Komodo was forced to lose material and the game was adjudicated on move 36. Komodo's position collapsed very quickly, quite unexpected for an engine of this strength.
The reverse games have been played and the first double RR is over. Stockfish is in the lead with a +6 score. Houdini had 4 wins in RR2 including one against Komodo, it is in second place. Ginkgo and Chiron close the table with a -4 score, Andscacs is only 0.5 a point ahead in 6th place. Fire in 4th is 0.5 points ahead of Ethereal, each has one win in their head to head games.
A few interesting games
Fire - Ethereal: Fire had a space advantage with increasing evals. Fire created a queen side passer, and though its king was exposed it attacked on the king side. After exchanging most pieces the game reached a QB vs QN position. Fire grabbed two pawns and reduced to a winning endgame. Interesting to note that Ethereal saw it was losing a long time before Fire did. A biased opening with two white wins.
Houdini - Chiron: The engines castled in opposite directions. Houdini had a space advantage, after the king side pawns stabilized it focused on the queen side. Chiron did not have enough defenders and it lost a pawn. Houdini kept pressing, it won a second pawn, and the game was adjudicated in a Q vs RB imbalance. Houdini's first win in the division.
Komodo - Stockfish: Komodo had an eval around 1 for more than 50 moves, with a rook for knight advantage. Stockfish traded down to a RR vs RB position and held the draw.
Komodo - Ginkgo: The center was blocked and the engines castled in opposite directions. The king side had an open file that Ginkgo guarded with its rooks. Komodo's eval jumped and it exchanged a pair of rooks and created a king side passer. Then it captured a pawn on the queen side and penetrated with its queen. Ginkgo's defense collapsed and the game was adjudicated. Komodo had a double win in this opening.
Ethereal - Andscacs: The engines were essentially shufflling for a long time. Evals started to climb after Ethereal opened up the position. The game reached a RBB vs RBN position with Ethereal a pawn up. Ethereal went after the black pawns and the game was adjudicated when it was 3 pawns up. Another biased opening with two white wins.
Houdini - Komodo: See featured game below.
Houdini - Ginkgo: Houdini pushed pawns on the king side, and when the time was right it attacked the pawns defending the black king. Evals increased quickly, Houdini won a rook for a bishop and the game was adjudicated in a QRR vs QRB position. Two back to back wins for Houdini.
Stockfish - Andscacs: Andscacs gave a knight for 3 pawns, it forced Stockfish's king to walk to the king side uncastled. The game reached a RRB vs RR position with increasing evals. Stockfish outplayed Andscacs in the endgame. Its rooks attacked the black pawns and king while it kept one pawn safe, then reduced to a winning bishop ending. A double win for Stockfish in the opening.
Houdini - Andscacs: Houdini created a queen side passer, and although Andscacs fought hard to keep it from advancing ultimately Houdini used it to win the game. The game was adjudicated in a QRB vs QRB position with the passer on the 6th rank.
Komodo - Ethereal: The game reached a QRR vs QRB position with Ethereal two pawns up and evals around 1. Ethereal's pieces were passive and its bishop almost trapped behind the pawns. Komodo weakened the black king side and captured a pawn, the game was adjudicate before Ethereal lost more material.
Stockfish - Chiron: Stockfish had an eval of about 1, Chiron held the position for over 50 moves. The engines opened files on both sides, Stockfish walked its king to the queen side and then patiently applied pressure on Chiron. The game reached a QRN vs QRN position and Stockfish captured a pawn. When it captured a second pawn the game was adjudicated.
Ginkgo - Stockfish: The game reached a R vs BN imbalance with Ginkgo two pawns up. Evals were close to 0 until move 40, then started to increase in favor of Stockfish. There was a long shuffle and then Ginkgo gave a pawn and opened the king side with pawn moves. Despite a pair of connected passers in the center for white, Stockfish thought it was winning. It reduced to a RR vs RBN position and advanced a passer to the 2nd rank. Ginkgo had to give a rook for a knight to get rid of the passer, leading to a won RB vs R endgame for Stockfish.
Featured game: Houdini - Komodo
Premier division, round 10
Link to game on TCEC
Komodo gave a bishop for 3 pawns, creating two connected passers in the center. After exchanging queens Houdini had an eval advantage under 1 with a bishop pair, though the black pawns looked intimidating.
Houdini blocked the passers with its pieces, with evals increasing. After the engines stabilized the king side pawns evals were over 1.5, though it seemed that Komodo built a strong pawn line across the board.
Houdini doubled rooks on the e file and then broke through the center giving a rook for a knight. In the RBB vs RR position Houdini's bishops were very strong, Komodo's king was trapped in the corner.
Within a few moves the black king was in a mating net, Komodo was forced to lose material and the game was adjudicated on move 36. Komodo's position collapsed very quickly, quite unexpected for an engine of this strength.
Monday, September 10, 2018
Season 13 premier division after RR1
Crosstable after RR1
Stockfish is leading the table with a +3 score and no loss, including a win against Komodo. Komodo is the only other engine with a positive score of +1. Houdini is the only other engine with no loss, it drew all the games in the RR.
Chiron is last with a score of -2, there is a good chance it will be relegated back to division 1. Ethereal has a 0 score so far, two wins (one against Fire) and two losses. It is quite possible it will survive this division.
Some of the openings were biased and it should be interesting to see the results of the reverse games in the next RR.
A few interesting games
Andscacs - Ginkgo: Andscacs pressed hard in the opening game. Its eval peaked over 1.5 despite being down an exchange. Ginkgo managed to stop connected passers, one on the 7th rank, in a QB vs QR position. The game ended in a draw.
Ethereal - Fire: Ethereal came out of the opening a pawn down but with an advanced passer in the center and increasing evals. Ethereal exchanged pieces, giving a rook for a bishop as well. The game reached a BB vs RB position, Ethereal 3 pawns up. Fire traded the rook to force an opposite color bishop ending, still Ethereal found the win. Ethereal with a win in its opening game, how far can it go in the premier division?
Stockfish - Komodo: Featured game, see below.
Ginkgo - Komodo: Komodo gave a bishop for two pawns early in the game. Ginkgo's king was exposed, Komodo did not attack and the engines shuffled for 20 moves. It seemed Ginkgo lost its patience, the position opened up and the engines exchanged queens, with evals increasing in favor of Komodo. Ginkgo's position collapsed, the game was adjudicated after Komodo won a piece and was 3 pawns up.
Fire - Chiron: Chiron moved its queen forward and Fire almost trapped it. By the time the queen found safety Fire attacked the back rank and black king with its rooks and queen. Fire won a bishop and the RN vs R ending was won for white.
Andscacs - Ethereal: Ethereal's 24th move led to a long series of exchanges and a RB vs RN position on move 36. Andscacs was two pawns up with eval over 1.5 and increasing. Ethereal tried to hold against two white passers, it managed to capture one but allowed Andscacs' rook to move forward and attack the black king. Andscacs found a way to exchange rooks and advance its king, winning the B vs N endgame.
Fire - Komodo: Fire was up a rook for a knight in a closed position. The engines shuffled for a very long time, both had very little time when Fire played several inaccuracies after move 98. The game reached a RRB vs RBN position with a pawn wall across the board. Only the black pieces could move freely, Komodo patiently maneuvered until it captured two pawns. Fire's position collapsed and the game was adjudicated.
Andscacs - Stockfish: Andscacs thought it was ahead when Stockfish's eval turned negative on move 31. The engines castled in opposite directions, Stockfish opened a file on the queen side with doubled rooks facing the white king. Andscacs traded Q for RB and the game reached a RBN vs QN position. It took Stockfish another 30 moves to win but there was never doubt it would.
Ethereal - Chiron: The engines castled in opposite directions, Ethereal pushed pawns on the king side towards the black king. Chiron exchanged pieces and gave a knight for pawns to open the queen side and counterattack. The game reached a RRB vs RR position, Chiron's king was trapped in the corner and the engines started to capture pawns. The game was adjudicated just before Chiron lost its last pawn.
Stockfish - Ethereal: The engines shuffled in an closed position and didn't seem to make progress. On move 45 Stockfish saw an opportunity and pushed pawns on the king side. After a long series of exchanges the game reached a RN vs R position, Stockfish converted the win without difficulty.
Komodo - Chiron: Komodo started a king side attack with a bishop sacrifice. After almost all pieces were exchanged Komodo was two pawns up in an opposite color bishop ending. Chiron held the draw but it took more than 200 moves before the evals were low enough to adjudicate.
Featured game: Stockfish - Komodo
Premier division, round 1
Link to game on TCEC
Stockfish's eval was over 1 after book, Komodo's eval remained mostly under 0.5. Stockfish gave a pawn to open the queen side. The position was unstable, with Komodo threatening a fork with one knight, Stockfish threatening to take the other knight, the b4 pawn pinned and rooks facing each other on the d file.
There was a series of exchanges that resolved the tension. Stockfish was ahead by a knight for 2 pawns and Komodo had connected passers on the queen side. Evals increased very slowly, Stockfish's eval was close to 2 while Komodo's was still under 1. There was a long PV agreement and it wasn't clear whether Stockfish could convert.
The engines followed the PV line and the game reached a QBN vs QB position on move 33. The pieces moved around and evals did not change a lot, on move 44 Stockfish exchanged queens.
Evals were almost constant for a very long time, and the endgame was very slow. Stockfish's bishop made sure the queen side pawns did not advance. In the end Stockfish moved its king forward and this broke Komodo's defense. Can Stockfish hold the reverse game?
Stockfish is leading the table with a +3 score and no loss, including a win against Komodo. Komodo is the only other engine with a positive score of +1. Houdini is the only other engine with no loss, it drew all the games in the RR.
Chiron is last with a score of -2, there is a good chance it will be relegated back to division 1. Ethereal has a 0 score so far, two wins (one against Fire) and two losses. It is quite possible it will survive this division.
Some of the openings were biased and it should be interesting to see the results of the reverse games in the next RR.
A few interesting games
Andscacs - Ginkgo: Andscacs pressed hard in the opening game. Its eval peaked over 1.5 despite being down an exchange. Ginkgo managed to stop connected passers, one on the 7th rank, in a QB vs QR position. The game ended in a draw.
Ethereal - Fire: Ethereal came out of the opening a pawn down but with an advanced passer in the center and increasing evals. Ethereal exchanged pieces, giving a rook for a bishop as well. The game reached a BB vs RB position, Ethereal 3 pawns up. Fire traded the rook to force an opposite color bishop ending, still Ethereal found the win. Ethereal with a win in its opening game, how far can it go in the premier division?
Stockfish - Komodo: Featured game, see below.
Ginkgo - Komodo: Komodo gave a bishop for two pawns early in the game. Ginkgo's king was exposed, Komodo did not attack and the engines shuffled for 20 moves. It seemed Ginkgo lost its patience, the position opened up and the engines exchanged queens, with evals increasing in favor of Komodo. Ginkgo's position collapsed, the game was adjudicated after Komodo won a piece and was 3 pawns up.
Fire - Chiron: Chiron moved its queen forward and Fire almost trapped it. By the time the queen found safety Fire attacked the back rank and black king with its rooks and queen. Fire won a bishop and the RN vs R ending was won for white.
Andscacs - Ethereal: Ethereal's 24th move led to a long series of exchanges and a RB vs RN position on move 36. Andscacs was two pawns up with eval over 1.5 and increasing. Ethereal tried to hold against two white passers, it managed to capture one but allowed Andscacs' rook to move forward and attack the black king. Andscacs found a way to exchange rooks and advance its king, winning the B vs N endgame.
Fire - Komodo: Fire was up a rook for a knight in a closed position. The engines shuffled for a very long time, both had very little time when Fire played several inaccuracies after move 98. The game reached a RRB vs RBN position with a pawn wall across the board. Only the black pieces could move freely, Komodo patiently maneuvered until it captured two pawns. Fire's position collapsed and the game was adjudicated.
Andscacs - Stockfish: Andscacs thought it was ahead when Stockfish's eval turned negative on move 31. The engines castled in opposite directions, Stockfish opened a file on the queen side with doubled rooks facing the white king. Andscacs traded Q for RB and the game reached a RBN vs QN position. It took Stockfish another 30 moves to win but there was never doubt it would.
Ethereal - Chiron: The engines castled in opposite directions, Ethereal pushed pawns on the king side towards the black king. Chiron exchanged pieces and gave a knight for pawns to open the queen side and counterattack. The game reached a RRB vs RR position, Chiron's king was trapped in the corner and the engines started to capture pawns. The game was adjudicated just before Chiron lost its last pawn.
Stockfish - Ethereal: The engines shuffled in an closed position and didn't seem to make progress. On move 45 Stockfish saw an opportunity and pushed pawns on the king side. After a long series of exchanges the game reached a RN vs R position, Stockfish converted the win without difficulty.
Komodo - Chiron: Komodo started a king side attack with a bishop sacrifice. After almost all pieces were exchanged Komodo was two pawns up in an opposite color bishop ending. Chiron held the draw but it took more than 200 moves before the evals were low enough to adjudicate.
Featured game: Stockfish - Komodo
Premier division, round 1
Link to game on TCEC
Stockfish's eval was over 1 after book, Komodo's eval remained mostly under 0.5. Stockfish gave a pawn to open the queen side. The position was unstable, with Komodo threatening a fork with one knight, Stockfish threatening to take the other knight, the b4 pawn pinned and rooks facing each other on the d file.
There was a series of exchanges that resolved the tension. Stockfish was ahead by a knight for 2 pawns and Komodo had connected passers on the queen side. Evals increased very slowly, Stockfish's eval was close to 2 while Komodo's was still under 1. There was a long PV agreement and it wasn't clear whether Stockfish could convert.
The engines followed the PV line and the game reached a QBN vs QB position on move 33. The pieces moved around and evals did not change a lot, on move 44 Stockfish exchanged queens.
Evals were almost constant for a very long time, and the endgame was very slow. Stockfish's bishop made sure the queen side pawns did not advance. In the end Stockfish moved its king forward and this broke Komodo's defense. Can Stockfish hold the reverse game?
Wednesday, September 5, 2018
Season 13 division 1 final results
Final crosstable
Ethereal and Chiron promote to the premier division, Booot and ChessBrain are relegated to division 2.
Promotion of Ethereal and Chiron was never in question, they both dominated the division from the start. Fizbo lost touch with the leaders in the second half of the division, it lost three games, including a loss to Ethereal and to Chiron.
The relegation race was very close with 5 candidate engines. ChessBrain dropped to last place after a score of -5 in the second half of the division. Jonny with a score of +1 in the second half managed to climb out of the last place. Booot scored -1 and its only win of the division, it almost survived relegation. Its early crashes were its downfall, both because of the tiebreak and because of the lost points.
The premier division is about to start with Stockfish, Komodo, Houdini, Fire, Andscacs, Ginkgo, Ethereal and Chiron playing. This is the main event of the season where we get to see the really top chess engines competing, with long games and the highest level of chess. Stockfish is the clear favorite, the winner of the last two seasons. Houdini and Komodo are expected to compete for a place in the superfinal. Recall that last season Komodo won the premier league ahead of Stockfish, with Houdini only one point behind. It is unknown how well the other engines will play. Fire has been a constant 4th in the last seasons, Ethereal may also fight for 4th according to its author Andrew Grant. It is incredible that Ethereal started season 13 in division 3 and won three division in a row.
Good luck to all!
A few interesting games
Chiron - Fritz: Fritz created a queen side passer early in the game. At first it appeared the black queen was in trouble, but it got away and Fritz connected its passer on the 3rd rank with a bishop. The game reached a RBB vs RBB position and evals gradually increased in favor of Fritz. The engines exchanged pieces and pawns, Chiron could not get rid of the black passer. In the end only bishops remained and the passer was good for a win for Fritz. A surprise loss for Chiron.
Fritz - Booot: Booot chose a RN vs Q imbalance early in the game, this turned out to be a bad idea. The black king was exposed, Chiron took over the 7th rank and together with a strong bishop pair threatened mate. The game was adjudicated before Booot lost its queen. Two Fritz wins in a row, it moves away from the relegation zone.
Jonny - Chiron: Jonny took a poisoned pawn with its queen early in the game. This quickly led to a R vs BN imbalance and negative evals around 3. It took Chiron close to 30 moves to get the win in a RN vs R endgame.
Ethereal - Fizbo: Ethereal created a central passer early in the game. A strong king side attack gave Ethereal a R vs B exchange advantage and evals over 2.5. Fizbo's compensation was the exposed white king, for a while Fizbo's eval came down below 1 while it made checks. Evals came back up and continued to increase when the white pieces sheltered the king and Ethereal had the initiative again.The game reached a RNB vs RB position and was adjudicated before the endgame was played out. This was the first loss for Fizbo in the division.
Chiron - ChessBrain: Chiron was a pawn up early in the game. The engines exchanged most of the pieces and only RN vs RB remained on move 23. Chiron created a queen side passer and reduced to a winning rook ending.
Fizbo - Fritz: Fizbo trapped a black rook and went up R vs N exchange. Fritz tried to counter with a queen side passer, Fizbo made sure it won't advance. Fizbo created a passer in the center and then exchanged down to a RB vs BB position. The white passer was worth a piece and it gave Fizbo the win.
Jonny - Laser: See my live blog of the game. Jonny had a R vs B exchange advantage and the game reached a RRB vs RBB position on move 30. Jonny controlled the 7th rank and after exchanging a pair of rooks it managed to get a winning endgame. Jonny's win complicated the bottom of the table.
Ethereal - Chiron: See featured game below. Ethereal wins and evens the head to head score against Chiron.
Laser - ChessBrain: Laser had an eval over 2 when the position opened up in a RRB vs RRN position. The game reached a rook ending with Laser a pawn up. ChessBrain did not have tablebase access and didn't realize it was lost until the game reached a tablebase adjudication.
ChessBrain - Fritz: ChessBrain went up a pawn early in the game. After some shuffling the engines exchanged pieces until only B vs N remained, Fritz had to block the white passer on the queen side and ChessBrain found a zugzwang win.
Ethereal - Laser: Laser got into trouble very early. Ethereal didn't castle, instead it launched a deadly king side attack. Evals shot up quickly, Laser exchanged most pieces and lost only a little material. The game reached a R vs B position, and an easy win for Ethereal.
Fritz - Ethereal: Evals were stable and close to 0 until Fritz decided to sacrifice a knight. It got 3 pawns in return and two passers, but evals became negative and increased slowly. Ethereal exchanged pieces until only BNN vs BB remained, then it captured the white passers with evals over 2. For a while it seemed Fritz might be able to hold a draw with its bishop pair, but then it blundered the game away.
Jonny - ChessBrain: Jonny won a pawn, then after some preparation exchanged down to a RB vs RB position. The endgame was very slow, Jonny captured a second pawn and had a king side passer. ChessBrain's lack of tablebase support was evident again, Jonny reduced to a winning 6-man position and ChessBrain thought it still had a chance.
After RR3 the standings are Ethereal +9, Chiron +5, Fizbo +1, Fritz -2, Jonny -3, ChessBrain -3, Laser -3, Booot -4. There are 5 engines fighting against relegation, Booot's crashes against ChessBrain and Fritz were very unfortunate.
Fizbo - ChessBrain: ChessBrain chose to open the king side, putting its king at risk. Fizbo was up a pawn with a bishop pair facing ChessBrain's knight pair, ChessBrain had an advanced passer in the center as compensation. The game reached a RBB vs RNN position, the bishops were very strong and the exposed black king was an easy target. ChessBrain lost a piece for pawns, Fizbo won the endgame.
Fritz - Chiron: Fritz had a small eval advantage for the first 50 moves, when the position opened evals became slightly negative but still close to 0. The game seemed to be heading for a draw, after a long shuffle Chiron took the initiative on move 80. It took a while but after most pieces were exchanged the game reached a RB vs Q ending. Chiron captured the remaining white pawns and reduced to a winning 6-man position.
Ethereal - ChessBrain: Ethereal gave a knight for 3 pawns. The game reached a RB vs RBN position and for a while it seemed ChessBrain can hold. On move 64 ChessBrain blundered and Ethereal's eval started to jump. It took Ethereal 20 more moves to reduce to a winning rook ending.
Only 4 rounds to go, the bottom of the table is Fritz -3, Jonny -3, Laser -3, Booot -4, ChessBrain -5. ChessBrain lost twice, but its remaining games are only against the other bottom 5 engines. All other contestants have at least one game to play against the top 3, Booot has to face all 3. Nothing is decided yet.
Fritz - Fizbo: Fritz was a pawn up early in the game, with an eval advantage that increased over 1. Fizbo gave a second pawn, opened the king side and threatened the white king. Fritz exchanged pieces and the game reached a QBN vs QR position. Evals slowly came down, then shot up over 2 after an unexpected Fizbo blunder. Fritz drove the black king out of the corner and captured a pawn, evals slowly increased until the game was adjudicated. An unexpected win for Fritz.
Booot - ChessBrain: The engines castled in opposite directions, ChessBrain gave a pawn to open the queen side and tried to attack the white king. After a series of exchanges the game reached a RN vs Q imbalance, Booot 2 pawns up and evals over 1. ChessBrain's attack on the white king was not strong enough, a white passer forced ChessBrain to lose a piece. Booot's material advantage was enough for a win. This is Booot's first win of the division.
Fizbo - Chiron: The game started in a closed position. Chiron opened the king side and had much more space. It increased the pressure with the queen and a passer on the queen side and rooks on the king side. The game was adjudicated before Fizbo lost material. Two straight losses for Fizbo.
Now only 2 rounds to go, the bottom of the table is Fritz -2, Jonny -3, Laser -3, Booot -3, ChessBrain -6. ChessBrain is very close to being relegated back to division 2, Fritz and Booot improved their chances to survive.
Booot - Chiron: Booot had a small eval advantage from the opening, though Chiron had a queen side passer. Chiron took over after Booot gave a bishop for three pawns including the black passer. The game reached a R vs RB position, Chiron gradually captured and exchanged pawns. The game ended in a tablebase win for black. This loss means that Booot must win its last game to have a chance of surviving.
Fizbo - Booot: Fizbo had the advantage in a RRB vs RRB position, the game ended in a tablebase draw. Booot cannot survive, it will lose any tiebreak because of crashes.
Chiron - Laser: Chiron created a passer on the queen side. As the engines exchanged pieces the evals increased gradually, Chiron also had a bishop pair advantage. Eventually Laser lost a piece to get rid of the passer, the game reached a QBB vs QB position. It took Chiron a while, and perhaps Laser blundered but in the end Chiron found the win.
Ethereal - Fritz: Ethereal was a pawn down when suddenly its eval jumped over 3. Apparently Fritz ignored the danger to its king and was late in developing its queen side pieces, and it was slow to realize it was losing. Fritz gave a knight and exchanged pieces, its king was still vulnerable in a QRN vs QR position and the game was soon adjudicated.
Featured game: Ethereal - Chiron
Division 1, round 18
Link to game on TCEC
Evals were close to 0 with a small advantage to Ethereal. After the opening Ethereal had an isolated pawn in the center, Chiron moved its rook forward to apply pressure on it.
The rook immediately became a target. Ethereal could exchange it for a bishop but it made some preparations first. When the exchange was made Ethereal also had passers on the queen side. Evals were over 1 and increasing.
After exchanging queens the game reached a RBN vs BBN position. Chiron had an advanced passer but after Ethereal got rid of the black LS bishop Chiron lost control of the the queening square.
Ethereal used attacks on the black king and pieces to advance its passer to the 7th rank and get a winning position.
Ethereal and Chiron promote to the premier division, Booot and ChessBrain are relegated to division 2.
Promotion of Ethereal and Chiron was never in question, they both dominated the division from the start. Fizbo lost touch with the leaders in the second half of the division, it lost three games, including a loss to Ethereal and to Chiron.
The relegation race was very close with 5 candidate engines. ChessBrain dropped to last place after a score of -5 in the second half of the division. Jonny with a score of +1 in the second half managed to climb out of the last place. Booot scored -1 and its only win of the division, it almost survived relegation. Its early crashes were its downfall, both because of the tiebreak and because of the lost points.
The premier division is about to start with Stockfish, Komodo, Houdini, Fire, Andscacs, Ginkgo, Ethereal and Chiron playing. This is the main event of the season where we get to see the really top chess engines competing, with long games and the highest level of chess. Stockfish is the clear favorite, the winner of the last two seasons. Houdini and Komodo are expected to compete for a place in the superfinal. Recall that last season Komodo won the premier league ahead of Stockfish, with Houdini only one point behind. It is unknown how well the other engines will play. Fire has been a constant 4th in the last seasons, Ethereal may also fight for 4th according to its author Andrew Grant. It is incredible that Ethereal started season 13 in division 3 and won three division in a row.
Good luck to all!
A few interesting games
Chiron - Fritz: Fritz created a queen side passer early in the game. At first it appeared the black queen was in trouble, but it got away and Fritz connected its passer on the 3rd rank with a bishop. The game reached a RBB vs RBB position and evals gradually increased in favor of Fritz. The engines exchanged pieces and pawns, Chiron could not get rid of the black passer. In the end only bishops remained and the passer was good for a win for Fritz. A surprise loss for Chiron.
Fritz - Booot: Booot chose a RN vs Q imbalance early in the game, this turned out to be a bad idea. The black king was exposed, Chiron took over the 7th rank and together with a strong bishop pair threatened mate. The game was adjudicated before Booot lost its queen. Two Fritz wins in a row, it moves away from the relegation zone.
Jonny - Chiron: Jonny took a poisoned pawn with its queen early in the game. This quickly led to a R vs BN imbalance and negative evals around 3. It took Chiron close to 30 moves to get the win in a RN vs R endgame.
Ethereal - Fizbo: Ethereal created a central passer early in the game. A strong king side attack gave Ethereal a R vs B exchange advantage and evals over 2.5. Fizbo's compensation was the exposed white king, for a while Fizbo's eval came down below 1 while it made checks. Evals came back up and continued to increase when the white pieces sheltered the king and Ethereal had the initiative again.The game reached a RNB vs RB position and was adjudicated before the endgame was played out. This was the first loss for Fizbo in the division.
Chiron - ChessBrain: Chiron was a pawn up early in the game. The engines exchanged most of the pieces and only RN vs RB remained on move 23. Chiron created a queen side passer and reduced to a winning rook ending.
Fizbo - Fritz: Fizbo trapped a black rook and went up R vs N exchange. Fritz tried to counter with a queen side passer, Fizbo made sure it won't advance. Fizbo created a passer in the center and then exchanged down to a RB vs BB position. The white passer was worth a piece and it gave Fizbo the win.
Jonny - Laser: See my live blog of the game. Jonny had a R vs B exchange advantage and the game reached a RRB vs RBB position on move 30. Jonny controlled the 7th rank and after exchanging a pair of rooks it managed to get a winning endgame. Jonny's win complicated the bottom of the table.
Ethereal - Chiron: See featured game below. Ethereal wins and evens the head to head score against Chiron.
Laser - ChessBrain: Laser had an eval over 2 when the position opened up in a RRB vs RRN position. The game reached a rook ending with Laser a pawn up. ChessBrain did not have tablebase access and didn't realize it was lost until the game reached a tablebase adjudication.
ChessBrain - Fritz: ChessBrain went up a pawn early in the game. After some shuffling the engines exchanged pieces until only B vs N remained, Fritz had to block the white passer on the queen side and ChessBrain found a zugzwang win.
Ethereal - Laser: Laser got into trouble very early. Ethereal didn't castle, instead it launched a deadly king side attack. Evals shot up quickly, Laser exchanged most pieces and lost only a little material. The game reached a R vs B position, and an easy win for Ethereal.
Fritz - Ethereal: Evals were stable and close to 0 until Fritz decided to sacrifice a knight. It got 3 pawns in return and two passers, but evals became negative and increased slowly. Ethereal exchanged pieces until only BNN vs BB remained, then it captured the white passers with evals over 2. For a while it seemed Fritz might be able to hold a draw with its bishop pair, but then it blundered the game away.
Jonny - ChessBrain: Jonny won a pawn, then after some preparation exchanged down to a RB vs RB position. The endgame was very slow, Jonny captured a second pawn and had a king side passer. ChessBrain's lack of tablebase support was evident again, Jonny reduced to a winning 6-man position and ChessBrain thought it still had a chance.
After RR3 the standings are Ethereal +9, Chiron +5, Fizbo +1, Fritz -2, Jonny -3, ChessBrain -3, Laser -3, Booot -4. There are 5 engines fighting against relegation, Booot's crashes against ChessBrain and Fritz were very unfortunate.
Fizbo - ChessBrain: ChessBrain chose to open the king side, putting its king at risk. Fizbo was up a pawn with a bishop pair facing ChessBrain's knight pair, ChessBrain had an advanced passer in the center as compensation. The game reached a RBB vs RNN position, the bishops were very strong and the exposed black king was an easy target. ChessBrain lost a piece for pawns, Fizbo won the endgame.
Fritz - Chiron: Fritz had a small eval advantage for the first 50 moves, when the position opened evals became slightly negative but still close to 0. The game seemed to be heading for a draw, after a long shuffle Chiron took the initiative on move 80. It took a while but after most pieces were exchanged the game reached a RB vs Q ending. Chiron captured the remaining white pawns and reduced to a winning 6-man position.
Ethereal - ChessBrain: Ethereal gave a knight for 3 pawns. The game reached a RB vs RBN position and for a while it seemed ChessBrain can hold. On move 64 ChessBrain blundered and Ethereal's eval started to jump. It took Ethereal 20 more moves to reduce to a winning rook ending.
Only 4 rounds to go, the bottom of the table is Fritz -3, Jonny -3, Laser -3, Booot -4, ChessBrain -5. ChessBrain lost twice, but its remaining games are only against the other bottom 5 engines. All other contestants have at least one game to play against the top 3, Booot has to face all 3. Nothing is decided yet.
Fritz - Fizbo: Fritz was a pawn up early in the game, with an eval advantage that increased over 1. Fizbo gave a second pawn, opened the king side and threatened the white king. Fritz exchanged pieces and the game reached a QBN vs QR position. Evals slowly came down, then shot up over 2 after an unexpected Fizbo blunder. Fritz drove the black king out of the corner and captured a pawn, evals slowly increased until the game was adjudicated. An unexpected win for Fritz.
Booot - ChessBrain: The engines castled in opposite directions, ChessBrain gave a pawn to open the queen side and tried to attack the white king. After a series of exchanges the game reached a RN vs Q imbalance, Booot 2 pawns up and evals over 1. ChessBrain's attack on the white king was not strong enough, a white passer forced ChessBrain to lose a piece. Booot's material advantage was enough for a win. This is Booot's first win of the division.
Fizbo - Chiron: The game started in a closed position. Chiron opened the king side and had much more space. It increased the pressure with the queen and a passer on the queen side and rooks on the king side. The game was adjudicated before Fizbo lost material. Two straight losses for Fizbo.
Now only 2 rounds to go, the bottom of the table is Fritz -2, Jonny -3, Laser -3, Booot -3, ChessBrain -6. ChessBrain is very close to being relegated back to division 2, Fritz and Booot improved their chances to survive.
Booot - Chiron: Booot had a small eval advantage from the opening, though Chiron had a queen side passer. Chiron took over after Booot gave a bishop for three pawns including the black passer. The game reached a R vs RB position, Chiron gradually captured and exchanged pawns. The game ended in a tablebase win for black. This loss means that Booot must win its last game to have a chance of surviving.
Fizbo - Booot: Fizbo had the advantage in a RRB vs RRB position, the game ended in a tablebase draw. Booot cannot survive, it will lose any tiebreak because of crashes.
Chiron - Laser: Chiron created a passer on the queen side. As the engines exchanged pieces the evals increased gradually, Chiron also had a bishop pair advantage. Eventually Laser lost a piece to get rid of the passer, the game reached a QBB vs QB position. It took Chiron a while, and perhaps Laser blundered but in the end Chiron found the win.
Ethereal - Fritz: Ethereal was a pawn down when suddenly its eval jumped over 3. Apparently Fritz ignored the danger to its king and was late in developing its queen side pieces, and it was slow to realize it was losing. Fritz gave a knight and exchanged pieces, its king was still vulnerable in a QRN vs QR position and the game was soon adjudicated.
Featured game: Ethereal - Chiron
Division 1, round 18
Link to game on TCEC
Evals were close to 0 with a small advantage to Ethereal. After the opening Ethereal had an isolated pawn in the center, Chiron moved its rook forward to apply pressure on it.
The rook immediately became a target. Ethereal could exchange it for a bishop but it made some preparations first. When the exchange was made Ethereal also had passers on the queen side. Evals were over 1 and increasing.
After exchanging queens the game reached a RBN vs BBN position. Chiron had an advanced passer but after Ethereal got rid of the black LS bishop Chiron lost control of the the queening square.
Ethereal used attacks on the black king and pieces to advance its passer to the 7th rank and get a winning position.
Monday, September 3, 2018
Season 13 division 1 statistics
Draw rate, wins
Final draw rate was 62.5%.
Game termination
The three most common game termination causes were:
33.9% - TCEC draw rule
25% - TCEC win rule
24.1% - SyzygyTB
There were 2 crashes in the division.
Moves per game
Median= 55.3
Average= 61.1
There were only 7 games longer than 100 moves, the longest was 157 moves (Jonny - Laser, round 4, draw).
Time per game (hours)
Median= 2:06
Average= 2:04
Openings
There were 2-move book openings in this stage chosen by Cato. Each opening was repeated 4 times in a round, and then again in the reverse games round. In total 14 2-move openings were used. The first letter of the ECO codes was distributed as follows:
If we use the opening 'family name' (using format FAMILY_NAME: VARIANT....) the top 3 are:
QGD - 16 times
Sicilian - 16 times
English - 11 times
The engines had a lot of freedom to choose the opening variant. Only 19.6% of the game pairs repeated the same ECO code twice, and 14.3% repeated the same opening variant. In 14.3% of the game pairs the ECO first letter was not repeated twice.
Reverse pairs, wins
Reverse pairs, same moves
Pairs of reverse games diverged very quickly, 91.2% of the pairs diverged at most after 1 move. The longest repeated move sequence in a game pair was only 9 plys long.
Final draw rate was 62.5%.
Game termination
The three most common game termination causes were:
33.9% - TCEC draw rule
25% - TCEC win rule
24.1% - SyzygyTB
There were 2 crashes in the division.
Moves per game
Median= 55.3
Average= 61.1
There were only 7 games longer than 100 moves, the longest was 157 moves (Jonny - Laser, round 4, draw).
Time per game (hours)
Median= 2:06
Average= 2:04
Openings
There were 2-move book openings in this stage chosen by Cato. Each opening was repeated 4 times in a round, and then again in the reverse games round. In total 14 2-move openings were used. The first letter of the ECO codes was distributed as follows:
If we use the opening 'family name' (using format FAMILY_NAME: VARIANT....) the top 3 are:
QGD - 16 times
Sicilian - 16 times
English - 11 times
The engines had a lot of freedom to choose the opening variant. Only 19.6% of the game pairs repeated the same ECO code twice, and 14.3% repeated the same opening variant. In 14.3% of the game pairs the ECO first letter was not repeated twice.
Reverse pairs, wins
Reverse pairs, same moves
Pairs of reverse games diverged very quickly, 91.2% of the pairs diverged at most after 1 move. The longest repeated move sequence in a game pair was only 9 plys long.
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