Thursday, July 26, 2018

Waiting for season 13, short vacation

Update 29.7.18:

Chessdom has posted an update. Season 13 is due to start on Friday 3.8.18, the undisclosed NN engine is called DeusX and the hardware will indeed include a CPU machine for traditional engines and a GPU machine for the NN engines. There are still 3 engines in division 4 whose identity has not been published yet.

I am still on vacation, and will probably miss division 4 

Orignal post - 26.7.18: 

The TCEC website is currently unavailable as Season 13 is being prepared in the background. There has been no official press release on chessdom or on facebook yet. According to the chat we are expecting new GPU hardware for this season, and at least two neural network based engines using it - Leela and an undisclosed mystery engine.

The site administrator for TCEC has changed again. The previous administrator KnightMoves left quite suddently, I did not witness the event and I don't know what happened exactly. As a result the new GUI that was developed during the past few months is gone as well. The new administrator will have to get acquainted with the system quickly, including the new hardware. I wish him good luck and I hope that TCEC will run smoothly.

I am on vacation for a few weeks and will miss the start of the season, if indeed it starts soon as planned. I hope to start posting again when I get back in the second half of August.

Sunday, July 8, 2018

Season 12 superfinal, games 97-100 and final results

The season 12 superfinal is over, Stockfish wins 29-9 with 62 draws. The final draw rate is 62%, one of the lowest ever in a TCEC superfinal. Stockfish added two more wins in the last two openings.

Stockfish pushed its king side pawns at the start of game 49.1, its king was quite exposed and Komodo controlled the long diagonals surrounding it. Still it was Stockfish that was ahead on evals, all its pieces headed for the king side.



Stockfish blocked the long diagonal with pieces, improving its king safety. Stockfish continued to push pawns on the king side, Komodo was careful not to open files and it allowed Stockfish's knight to fork two rooks. Evals continued to increase, a king side attack was unavoidable.



Stockfish won a rook for  knight and then opened the king side. After a series of exchanges only RB vs BN were left, the black bishop was stuck in the center many moves away from finding a useful square.




The white rook moved to the 7th rank and the white king move forward to support the pawns in the center. The game was adjudicated before Komodo started to lose pawns.

In the reverse game 49.2 Komodo did not push pawns on the king side, its king remained safe. Stockfish pushed pawns on the queen side and kept its pieces behind the pawn line. The engines started to shuffle on move 28, Komodo escaped the 50 move draw at the last minute and exchanged queens. Shuffling resumed, now Stockfish had an eval advantage and it exchanged rooks as the 50 move counter reached 0. Both engines finally lowered their evals to end the game in a repetition draw.

The 50th and last opening started with a very long book sequence 19 moves long. In game 50.1 Stockfish initiated a king side attack immediately, giving two pawns and opening files. On move 28 its eval was already over 3.




Stockfish threatened mate on the g file, it captured the black LS bishop which defended the g8 square. Komodo chose to ignore the offered rook and instead exchanged as many pieces as it could. On move 38 only RBN vs RB remained.



The immediate mate threat was removed but now Stockfish was a piece up, the pawns started to fall and Komodo had no counter. The game was soon adjudicated.

The reverse game 50.2 was much more quiet. The king side remained closed and the evals were close to 0. The engines exchanged pieces and on move 32 only QRB vs QRB remained. The game reached a bishop ending and a quick draw.

Saturday, July 7, 2018

Season 12 superfinal, games 93-96

After 96 games Stockfish leads 27-9 with 60 draws. The draw rate continues to be low, now at 62.5%. Stockfish extends its lead again, Komodo wins in a biased opening for the fifth time.

Stockfish started game 47.1 a pawn up with an advanced central passer on the 6th rank. The white king was exposed a little despite castling. Komodo managed to regain the pawn and to exchange a few pieces on the queen side.



Stockfish pushed pawns on the king side and the evals started to increase. The engines continued to exchange pieces and the game reached a QRB vs QRN position. Komodo had a queen side passer, and the white king seemed to be open to attacks, yet Stockfish's eval was over 3.



Stockfish opened the g file and got a pawn to h7. Komodo was careful not to open the h file as well and tried to hide its king behind the white pawn. The combination of an advanced passer supported by the queen and an attack on the black king with the queen and rook was too much for Komodo. The game was soon adjudicated.

The reverse game 47.2 started similarly. Komodo did not push pawns on the king side. Instead the engines continued to exchange pieces and by move 34 only BN vs BN remained. Komodo's central passer and Stockfish's queen side passer canceled each other out, the game was adjudicated after a long shuffle.

In game 48.1 the engines castled in opposite directions. Stockfish gave a pawn, opened its king side and prepared an attack. Meanwhile, Komodo cleared its queen side pawns and prepared an attack there. There was a very long PV agreement on move 18.



The engines played the line they predicted, which was very wild including a black rook sacrifice and a white queen sacrifice. By move 33 the game reached an unusual RBB vs Q position, Stockfish's eval was over 4.




Stockfish's king found a square where it could not be attacked by the black queen. The evals constantly increased as the engines moved their pieces, though it was hard to see what Stockfish had in mind. Komodo appeared to be in zugzwang, it made pawn moves and then its king moved away from the pawns. Stockfish managed to get its rook to the back rank and from there to attack the pawn on a6.




The two a pawns were quickly captured, Stockfish now has a queen side passer and Komodo couldn't stop it without losing the queen.

In game 48.2 the engines castled in opposite directions again. Komodo did not push pawns on the king side which remained intact. Stockfish gave a pawn and opened the queen side, then it lined its major pieces on the c file facing the white king. Komodo stopped the attack easily, evals increased to around 1. Komodo opened the king side, the engines exchanged queens and Komodo gave a rook for a bishop to keep the c file blocked. The game reached a RBN vs RRB position, Komodo two pawns up.




Both engines pushed passers in the center. In a series of exchanges Stockfish lost a rook for a knight and both passers were captured, leaving a RB vs RB position with Komodo two pawns up. Stockfish managed to get a pawn back, Komodo had a king side passer that started to advance.



Stockfish tried to counter with its queen side passer, the white bishop controlled its final square. It took a while but eventually Stockfish could not block the white passer on the king side. Komodo pushed the pawn to h7, when it captured the black passer the game was adjudicated. Another Komodo win in a biased opening, like the previous Komodo win.

Friday, July 6, 2018

Season 12, superfinal statistics

Draw rate, wins


Final draw rate was 62%, very low compared to previous superfinals.

Game termination

The three most common game termination causes were:
38% - TCEC win rule
35% - TCEC draw rule
16% - SyzygyTB


Moves per game



Median=59.5
Average=65.9

The distribution has a right tail but not very long. There were only 8 100+ move games, including one that was exceptionally long at 238 moves.
 
Time per game (hours)
 

Median= 4:05
Average=4:00

The distribution has a left ridge, almost a bimodal distribution. Of the 25 games that were shorter than 3.5 hours 22 were draws, the medium length for these games was 46.5 moves.

Openings

There were variable length book openings in this stage chosen by Jeroen.
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:

King's Indian - 14 times
Sicillian - 10 times
KGA - 10 times

Almost all of the book lines had the same ECO codes in reverse games, except for one paired game - games 4.1 and 4.2 were two close variants of the Dutch opening A97 and A98. There were 2 game pairs with different opening variants.

Reverse pairs, wins



There was 5 biased openings with wins for both engines. This is a side effect of the opening choices that resulted in so many decisive games. On the other hand there was one opening where Stockfish won both games, this also happened once in the season 11 superfinal.


Reverse pairs, same moves  

Reverse games diverged very quickly, 40% diverged immediately after book, 74% diverged at most after two plys. Games 47.1 and 47.2 repeated 16 plys after book before diverging, and still Stockfish won as white and drew as black.



Season 12 superfinal, games 89-92

After 92 games Stockfish leads 25-8 with 59 draws. The draw rate continues to be low, now at 64.1%. Komodo finally gets a win, even though it was a biased opening.

Stockfish started game 45.1 with an eval over 1 that increased slowly. The center and queen side were blocked and the engines mostly shuffled for a while. The evals moved faster when Stockfish shifted its pieces to the king side and made a small hole in the pawn wall.




Stockfish doubled its rooks on the h file. Komodo gave a knight in an attempt to allow its pieces to get to the king side. Stockfish gave the knight back, creating a connected pair of passers on the queen side.




Stockfish had threats on both sides of the board and Komodo's defense collapsed. Stockfish broke through the king side and Komodo did not have enough defenders. The game was adjudicated before Stockfish won more material, its PV showed mate.

Evals stayed relatively low at the start of game 45.2. All the pieces and almost all pawns remained on the board, the engines moved without making contact. Evals started to increase slowly after the engines opened the a file and Komodo got a rook into the 7th rank.




For a while Komodo prepared its attack, evals increasing with all pieces still on the board. On move 46 there were a few exchanges, and on move 55 the engines exchanged queens. Evals were over 2.5 by then.




Komodo broke through the pawn wall with a bishop sacrifice. It got the piece back a few moves later, and the game reached a RN vs RN position with Komodo a pawn up.




Komodo pushed the c pawn forward, Stockfish tried to counter with its e pawn but Komodo simply blocked it with the king. Stockfish had to lose its knight for the white passer. Finally a win for Komodo, the last one was on game 56, also a biased opening like this one.

Komodo kept its king in the center uncastled in game 46.1. Stockfish had an eval advantage of around 0.8, the engines exchanged pieces until only RRN vs RRB remained on move 30. Komodo pushed pawns on the queen side until they reached the white pawns and locked together. The engines shuffled for a while, then opened the position with pawns exchanges. The game reached a double rook ending and a perpetual check draw. In the reverse game 46.2 Stockfish castled despite the semi open files on the king side, its eval was even negative for a short while. The engines started to shuffle on move 32, and 30 moves later opened the position with exchanges. Komodo's eval came down, it pushed its queen side passers and Stockfish gave a rook for a knight to stop it. The game ended in a drawn RRN vs RBN position.

Thursday, July 5, 2018

Season 12 superfinal, games 83-88

After 88 games Stockfish leads 24-7 with 57 draws. The draw rate continues to be low, now at 64.8%. There are 12 games left, Stockfish is officially the winner of TCEC season 12. Komodo's last win was in game 56, since then Stockfish is leading 12-0.

The black king moved in the game 42.1 book sequence. Stockfish castled long and 
pushed pawns on the king side. Komodo let its king side rook out through the h file, but it was almost trapped by the white pawns. 



Stockfish threatened an attack on the g file, Komodo reacted by surrounding its king with pieces. Stockfish sacrificed a pawn and opened the f file, its eval jumped over 3.




Stockfish won a rook for a bishop and after several exchanges only RRN vs RBB were left.



Stockfish soon captured the g pawn. Komodo had a bishop pair, but its king was exposed and open to the rooks attacking. The game was adjudicated, Stockfish's PV showed how Komodo could lose a piece several moves later.

Evals stayed close to 0 in the reverse game 42.2. Komodo did not open the king side, instead it attacked in front of the pawns. Stockfish used its trapped king side rook to protect the g pawn, then it sacrificed a rook and counter attacked on the queen side. The black king was in danger, Komodo chose to end the game with a perpetual check draw.

Stockfish started game 43.1 with an eval close to 1. The engines kept exchanging pieces, and the evals fell to 0 after move 30. On move 40 only RB vs Q remained, both kings were exposed and the game ended with a series of checks. In the reverse game the evals fell to 0 almost immediately. Again the engines exchanged many pieces and on move 36 only QN vs QN remained. Both engines had advanced passers, Stockfish promoted first but had to promote to a knight with check to prevent mate on its king. After exchanging queens Stockfish gave a knight to stop the white passer, leading to a knight ending and a tablebase draw.

The 44th opening was another King's Gambit variant. In game 44.1 queens were exchanged early. Komodo was a pawn up and its king uncastled, Stockfish's king was exposed in the king side. Evals were negative but never more than 0.5, Stockfish had a bishop pair advantage and evals slowly came down. Komodo had a connected pair of passers on the king side, Stockfish managed to stop them and through a series of exchanges to reduce to a rook ending and a tablebase draw.

In game 44.2 evals were negative and constantly increased from the start. The king side remained relatively intact and Stockfish castled its king. Komodo had a bishop pair, Stockfish kept its pawn advantage from the opening and managed to place a knight on g3 in front of the white king. The engines exchanged queens on move 30, Stockfish's eval approaching 2.



The pawns on the queen side were all isolated, and they were targeted by the pieces of both engines. It took 15 moves of careful planning, eventually Stockfish was able to capture one of the doubled pawns on the d file.




Stockfish started to push pawns on the king side, its king moved forward to support its pawns. Komodo reacted by exchanging pieces, and on move 58 only BB vs BN remained.



The two extra pawns were stronger than the bishop pair. Komodo gave one of its bishops for two pawns and the B vs BN ending was a win for Stockfish.

Wednesday, July 4, 2018

Season 12 superfinal, games 75-82

After 82 games Stockfish leads 22-7 with 53 draws. The draw rate continues to be low, now at 64.6%. Stockfish adds two more wins. It has a 15 game lead with 18 games left, soon to be declared the winner of the match.

Game 38.1 started with Stockfish down a knight for two pawns and Komodo's king in the center after moving forward. Stockfish created a central passer, the black king walked to the queen side for safety. Stockfish also had the bishop pair advantage.




Evals increased very slowly. The white passer was the center of attention for a while, then through a series of exchanges only RBB vs RRN were left on move 30. Komodo captured the central passer but Stockfish was two pawns up, and the bishops were stronger in an open position.




Stockfish concentrated its efforts on the king side where it had a pawn majority. It managed to create a connected pair of passers and captured another pawn. The g pawn moved forward alone and reached the 6th rank, and the LS bishop kept all the white pawns protected.




Komodo's defense collapsed, it was forced to lose a rook for a bishop and Stockfish with 3 pawns up was winning in a RB vs RN position.

In the reverse game 38.2 Stockfish kept its king in the center, and it was Komodo that gave a bishop for a knight. After a series of exchanges Stockfish got rid of the passer and only RRN vs RRB were left on move 24. Komodo was a pawn up but evals fell quickly to 0. The engines traded pawns until the game was adjudicated a draw. What a contrast to the previous game.

The black queen captured two pawns early in game 39.1 opening the white queen side. Komodo kept its king in the center uncastled. Evals started to increase as Stockfish drove the black queen away. Then Stockfish trapped a knight in the corner and gave a third pawn to weaken the black king side. Stockfish's eval jumped over 1, Komodo thought long to evaluate its situation.




There were many black pieces on the king side, Stockfish sacrificed a knight to open the queen side. Komodo's king was in real danger, it exchanged rooks and gave a bishop back in an attempt to find safety for its king and to untangle its pieces on the king side.



Stockfish put the attack on the black king on hold and created a queen side passer. The black queen finally found a way out of the corner, it tried to attack the white king but couldn't achieve much on its own. Stockfish won a rook for a bishop and prepared a protected corridor for its passer.



Stockfish shifted again to attack the black king. It traded R for BN to reach a QBN vs QN position, the game was adjudicated a few moves later.

In the reverse game 39.2 Komodo drove the black queen away, this time Stockfish prepared a safe place for it on the queen side. This allowed Stockfish to castle safely, evals favored black. Komodo won a rook for a bishop and pushed a passer in the center. Stockfish stopped the passer and exchanged queens, with RRN vs RBN remaining on move 35. Evals dropped to 0 as Stockfish blocked the open files effectively, the game ended in a draw.

In game 40.1 the engines castled in opposite directions, Komodo castling long. Stockfish pushed pawns on the queen side, weakening the black king. Komodo cleared most of its king side pawns, and it had a supported passer in the center. The engines shuffled for a while and then through a series of exchanges the game reached a RB vs RN position. The game ended in a tablebase draw. In the reverse game Stockfish went a pawn up and did not castle its king. Komodo gave a second pawn and opened a file in the center, it prevented black from castling long with its rook and queen. Stockfish castled short, its king very exposed with the center and king side open. On move 40 only QRR vs QRR remained, the engines gradually traded pawns and then reduced to a drawn rook ending. Komodo refused to lower its eval, the game went on another 50 moves.

Stockfish kept its king uncastled in game 41.1. The engines exchanged pawns on the queen side, the white king walked to the king side and trapped a rook in the corner. The engines exchanged pieces, on move 35 only QRR vs QRR remained. Stockfish freed its trapped rook,  the engines exchanged a pair of rooks before the game was adjudicated a draw. In game 41.2 both engines castled, there were many early exchanges and only RBN vs RNN remained on move 21. The game reached a drawn rook ending.

Tuesday, July 3, 2018

Season 12 superfinal, games 71-74

After 74 games Stockfish leads 20-7 with 47 draws. The draw rate continues to be low, now at 63.5%. Stockfish added two wins, both in the same opening. This is a rare event in superfinals.

There was a material imbalance of BN vs R early in game 36.1, with the engines castling in opposite directions.


Both engines focused on the queen side. Stockfish created a pawn majority there, capturing a pawn. Komodo placed its major pieces on the open files and Stockfish had to keep its king safe. As the engines exchanges pieces the evals started to increase, Stockfish captured a second pawn and made passers out of its queen side pawns. Komodo captured on the king side, after another piece exchange only QBN vs QR remained.


The white a pawn started to march forward slowly, Stockfish used its pieces to support it while protecting its king. Komodo tried but couldn't stop the advancing pawn, on move 53 it reached the 6th rank.



The white pawn made another step forward and Komodo blocked with its rook. The black queen tried to attack the white king but it was not strong enough on its own. In the end Komodo was forced to lose its rook to stop the pawn, a win for Stockfish.

In game 36.2 the engines again castled in opposite directions. Stockfish opened the queen side and Komodo pushed pawns on the king side, yet both kings remained relatively safe. Evals remained close to 0 despite Komodo being a pawn up. There were many pieces left on the board in an open position but the engines could not find an effective way to attack.




The engines shuffled for 20 moves, then Stockfish moved its pawns on the king side and evals became negative and started to increase. After a few exchanges Stockfish had the bishop pair advantage, its pieces had a lot of space and it had a strong pawn formation on the king side.



The black king captured the h6 pawn, it did not need a shield anymore and it moved forward to support the pawns. After a pawn exchange Stockfish had a connected pair of passers on the king side. Komodo had to give a rook to take out one of the bishops, in an attempt to stop the passers from marching.




Stockfish was too strong. It drove the blocking knight away and then the pawns pushed forward, winning the game. An incredible double win for Stockfish in this opening.

Stockfish started game 37.1 with an eval close to 1. Komodo pushed pawns in the center, getting a pawn to e3 and a knight to f2, right in front of the white king. Through piece exchanges Stockfish had a passer on the e file as well. Stockfish avoided a repetition draw and took out the advanced pawn and knight for a rook. The game reached a QRN vs QRR position, evals fell to 0 as Komodo gave back the material and reduced to a drawn rook ending. In the reverse game 37.2 Komodo created a central passer and pushed it to the 6th rank. The engines focused their pieces around the passer, after a series of exchanges Stockfish removed it with QRB vs QRB remaining. The engines exchanged rooks and started to shuffle. After 20 moves Komodo captured a pawn and exchanged queens. This left an opposite color bishop ending, and though Komodo was two pawns up it couldn't convert the win. The engines wouldn't lower their evals, the game continued until move 145.

Monday, July 2, 2018

Season 12 superfinal, games 67-70

After 70 games Stockfish leads 18-7 with 45 draws. The draw rate continues to be low, now at 64.3%. Stockfish with two more wins, in the last 14 games the score is 6-0 for Stockfish.

In game 34.1 Stockfish pushed its central pawns and kept its king uncastled and exposed. Despite this its eval was over 1 and slowly increasing as the engines exchanged pieces. On move 27 only RRB vs RRN remained.



Stockfish's eval reached 2.5 and stayed there for a while as it was trying to find a way to break Komodo's defense. The engines played a long PV line that included trading the minor pieces, then on move 40 Stockfish's eval jumped over 3. What did it see?



Almost all the black pawns were isolated and difficult to protect. Komodo was close to zugzwang and it gave a pawn on the queen side. Stockfish had several easy targets, the white king moved to the queen side and a rook switched to the king side, causing Komodo to lose a second pawn.




Stockfish now had two passers on the queen side, it captured another pawn before the game was adjudicated.

In the reverse game 34.2 Komodo took the time to castle its king. The engines kept their pieces on the board much longer, the evals peaked around 0.6 and started to come down. After a series of exchanges the game reached a RBN vs RBN position. Komodo gave a bishop to create a passer on the queen side, Stockfish gave a rook to stop the passer. The game ended in a R vs B tablebase draw.

In game 35.1 Stockfish kept its king uncastled in the center. Komodo pushed pawns on the queen side and had a space advantage, Stockfish countered on the king side but evals turned negative and increasing. Komodo pushed the white pieces back and had strong central knights. The white king walked to the king side and the engines started to shuffle. Stockfish traded a bishop for one of the knights, allowing Komodo to get a passer on the 3rd rank, and shuffling resumed. On move 115 Komodo took a pawn to reset the 50-move counter, evals were over 2 and increasing. The position opened and most pieces were exchanged, leading to a QB vs QB position. Komodo took out white pawns and was 3 pawns up with evals over 4, Stockfish forced a queen exchange resulting in an opposite color bishop ending. Incredibly Stockfish was able to hold, the pawn structure and position of the kings did not allow Komodo to push its pawns forward. After another shuffle period Komodo moved a pawn, allowing Stockfish to take out 3 pawns for a bishop. The white king walked to the queen side corner and Komodo could not force it out. Stockfish pulled out an incredible draw, the longest game of the match so far at 238 moves.

In the reverse game 35.2 Komodo castled its king, Stockfish had a pawn majority on the queen side and Komodo had a central passer. Then Stockfish gave 3 pawns and captured a knight, giving Komodo a king side passer and opening the position.




The engines traded pawns and pieces. Stockfish lost its queen side pawns, and after exchanging a pair of rooks and the queens only R vs RN remained, Stockfish with one last pawn while Komodo had 4. Evals were negative over 1 with a long PV agreement that looked drawish. Then on move 55 Stockfish deviated from the line and its eval jumped over 6!!



A few moves later Komodo saw it was lost as well and the game was adjudicated. It was far from clear how Stockfish was going to win, its PV showed a line where the two white pawns were gone. Komodo however did not follow that line in its last move, and in its PV the pawns were still intact. An 8-man tablebase is needed to understand this fully.

Sunday, July 1, 2018

Season 12 superfinal, games 59-66

After 66 games Stockfish leads 16-7 with 43 draws. The draw rate continues to be low, now at 65.1%. Stockfish extends its lead with three more wins, it doesn't look like Komodo can come back with two thirds of the match over.

The engines castled in opposite directions in game 30.1. Stockfish pushed pawns on the king side while Komodo moved its pieces to the queen side. The white pawn storm looked intimidating, and Stockfish's eval jumped over 3. Komodo was less concerned, even when the h file opened it thought its king side pawns provided enough defense for its king.




Komodo continued to play on the queen side, its two knights had excellent outposts in the center. Stockfish ignored this and built a massive canon on the h file. Komodo finally saw the danger, it gave a rook for a knight in order to stop the f pawn from advancing and to keep the king side files closed.




It was too late, Stockfish sacrificed a rook and opened the h file. The game was adjudicated before Komodo lost its queen. This was the shortest decisive game of the match so far, only 38 moves.

In the reverse game 30.2 Komodo opened the center and did not attack on the king side. Evals stayed low and the engines exchanged their pieces. By move 31 only QRR vs QRR remained, the game ended in a tablebase draw.

Stockfish had a space advantage in a closed position in game 31.1, its eval climbing over 1. After exchanging queens Stockfish was a pawn up, the engines started to shuffle. There was another piece exchange and only RRN vs RRN remained. After another shuffle period Komodo captured a pawn and equalized material, evals came down to 0 and the game was adjudicated. In the reverse game 31.2 evals stayed low. Komodo gave a pawn and opened the center. After exchanging queens only RRN vs RRB remained, Komodo had a central passer. Both engines thought they had a small advantage, yet both could only shuffle pieces. The evals dropped to 0 only when the 50 move draw was getting near.

The 32nd opening was another King's Gambit variant. In game 32.1 the white king was uncastled in the center, Komodo gave 3 pawns and opened a central file. Stockfish's king side pieces were blocked until its king walked to the corner and found safety. Both evals were 0 for a long time, Komodo regained the pawns and the engines exchanged most of their pieces. The game ended in a tablebase draw.

In the reverse game 32.2 both kings stayed uncastled, all the white king side pawns were gone and Stockfish gave a rook for a bishop. Komodo's king walked to the queen side, blocking a rook. After exchanging queens evals favored black in an unusual position.




Komodo pushed pawns on the queen side and let its rook out of the corner. Evals gradually increased as Stockfish prepared its king side for its passers. Komodo created a passer in the center and exchanged bishops, the black knights dominated the center and restricted white's defense.





The black king side pawns slowly marched forward. Komodo exchanged a pair of knights and tried to push its d pawn but it was not enough. Stockfish's king came to support its pawns and the game was adjudicated before Komodo lost material.

Evals stayed close to 0 in game 33.1. The engines castled in opposite directions, Komodo pushed pawns and opened the queen side, Stockfish's king hid behind the black pawns. The white queen moved forward, Komodo avoided a queen exchange and ended the game in a repetition. The game was a miniature of 26 moves.

In game 33.2 both engines pushed pawns towards their opponent's king. At first the evals were close to 0, the pawns were stopped on both sides. Komodo's king was a little more exposed with a black pawn on a3, evals turned negative. Komodo prepared a king side attack, Stockfish exchanged pieces and gave a rook for a knight. On move 37 only RRB vs RBB remained, the white king was trapped in the corner.



Stockfish started to push its king side pawns. The black bishops were very effective at supporting the pawns and making sure the white pawns don't advance on the queen side. Stockfish moved its king to support the pawns, while Komodo had to free its king by capturing the pawn on a3. Stockfish managed to get a pawn to the 3rd rank supported by a bishop.




As the PVs predicted Komodo gave a rook to stop the passer, leading to a R vs RB ending. The last black pawn was enough for a win.