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.