Season 27 superfinal games 71-80

After 80 games Stockfish leads 27-16 with 37 draws. All the last 5 game pairs were drawn, 4 had two white wins. Stockfish continues to lead by 11 wins and there are 10 pairs left in the match. Leela's non-win streak is now 21.

Games 71-72 started with a 20-ply sideline in the King's Indian defense played in human chess. All pieces and pawns were on the board. In game 71 the engines exchanged minor pieces on the king side and then opened the e file. Evals slowly increased, there was a pawn exchange on the queen side. For a while Stockfish blocked the center with minor pieces, eventually Leela exchanged a pair of bishops and a pair of rooks. 

After a few shuffling moves Leela moved its rook to the e file and its queen moved forward on the queen side. A knight exchange created a white passer on e6 and reduced to a QRB vs QRN position. Stockfish pushed pawns and locked the king side, Leela exchanged queens and its passer reached d7.

Stockfish captured the white d passer, the engines traded pawns and Stockfish created a passer on the queen side while Leela had a pawn majority on the king side. Leela captured a pawn on the king side and pushed its passers, Stockfish had no good counter, it lost more material and the game ended in a tablebase win.

In game 72 the engines exchanged minor pieces on the king side and opened the e file as before, the continuation was a little different though there was a pawn exchange on the queen side. Stockfish's eval slowly increased, Leela's eval remained stable. The engines exchanged a pair of rooks, Stockfish captured a pawn on the queen side and Leela avoided a queen exchange. Stockfish created a passer on the queen side through a knight exchange, the game reached a QRB vs QRB position.

Stockfish moved the bishop to c4 to keep all its queen side pawns protected. Leela avoided exchanges, its eval increased a little and the engines shuffled for a while. Leela blocked the queen side and the b passer, on move 49 the queens were exchanged.

Stockfish used its king as an additional piece, first to support a pawn exchange on the king side that opened the f file, then to support a pawn exchange on the queen side that opened the c file. After a pawn trade Stockfish created a passer on the king side. Leela gave the knight for the b5 passer, Stockfish queened the king side passer to win. There were two white wins in this pair, Stockfish leads 24-13.

Games 73-74 started with a 24-ply sideline in the Ruy Lopez, Chigorin defense variation played in human chess. The center was blocked, all pieces and pawns were on the board. In game 73 the engines opened the b file and Stockfish created doubled passers on the a file. Then a minor piece exchange created moved one black passer to b3. Evals increased a little, Leela captured the black b passer and the engines exchanged a pair of rooks. Leela gave back the pawn and created a passer in the center. 

The engines mostly shuffled for a long time, their evals not changing a lot. The king side was locked, on move 63 the remaining rooks were exchanged. Evals started to increase again, Leela moved the queen forward and on move 79 the queens were exchanged. The game reached a BN vs BN position. 

Both knights captured pawns, Stockfish captured the b5, f3 and g4 pawns, but Leela captured the h6 pawn which was more important. Leela had two advanced passers, Stockfish lost its knight and the king stopped one passer. Leela gave the bishop to stop the black a passer, then queened its remaining passer. The game ended in a tablebase win.

In game 74 the engines played a while without exchanges, on move 22 the pawn exchanges started on the queen side, opening the a and b files. Both engines created a passer, the engines exchanged a pair of rooks. On move 38 Leela pushed the f pawn, this led to the opening of the g file. Stockfish's eval jumped over 2 while Leela's eval was low, it didn't expect Stockfish to capture the black passer on the 40th move.

Leela's eval jumped a few moves too late. The engines exchanged a pair of bishops and Stockfish moved its major pieces to the king side. The exchanges continued and the game reached a knight ending on move 60, with white two pawns up. Stockfish pushed two passers forward, when the white king moved to support them Leela could not avoid a queening. The game ended in mate. There were two white wins in this pair, Stockfish leads 25-14.

Games 75-76 started with a sideline in the Caro-Kann, two knights attack variation. In game 75 there was a pawn exchange on the queen side, both engines castled their kings and Leela had strong pawns in the center. The engines exchanged a pair of bishops, the white d pawn became a passer. On move 24 evals started to increase, a pawn exchange opened the f file. The queens moved to the king side, a series of exchanges opened the h file and exposed the black king, Leela was a pawn up. The white king had minimal pawn support but the g pawn was also a passer. The queens were exchanged on move 43.

Stockfish regained the pawn and exchanged a pair of rooks, reducing to a RBN vs RBN position. Leela captured a pawn again and then gave the g passer. The kings moved forward and after a while the remaining rooks were exchanged. Leela captured a pawn and the a6 pawn became an unstoppable passer. Stockfish pushed the b pawn but Leela captured it, Leela queened and mated. 

In game 76 evals increased steadily from the start. The engines exchanged pawns on the king side and castled their kings. Pawn exchanges on the queen side opened the a and c files, Leela created a passer there. The engines exchanged a pair of bishops, Stockfish pushed the h pawn and opened the h file. The engines exchanged a pair of rooks, then all remaining minor pieces. Stockfish created a passer in the center and the game reached a QR vs QR position. 

Leela couldn't protect both the b and d pawns, the white queen moved forward and captured the d5 pawn. The engines exchanged rooks and traded pawns, Stockfish pushed its passer to e6 and saw the win in its PV. The white king moved forward and captured another pawn, the queens were exchanged and the game ended in a tablebase win. There were two white wins in this pair, Stockfish leads 26-15.

Games 77-78 started with a sideline in the Dutch defense, Queen's knight variation. All pieces and pawns were on the board, both kings were castled. In game 77 there was a pawn exchange in the center, evals came down quickly and the engines exchanged a few minor pieces. The e file opened and there were more exchanges, the game reached a queen ending and was adjudicated on move 44. In game 78 there were no exchanges right after the start, a few moves later there were pawn exchanges on the queen side. The black queen moved forward on the king side and there was a pawn exchange there. Evals started to come down, the black queen retreated and the engines shuffled for a while. On move 39 there was a minor piece exchange, first pieces off the board. Then queens were off in a series of exchanges, both engines had a passer and Leela had a bishop pair advantage. Stockfish captured a pawn and the game reached a RRN vs RRB position. Stockfish captured more pawns, but Leela ended the game in perpetual check and a repetition.

Games 79-80 started with a 22-ply rare sideline of the Benoni defense, Taimanov variation. There was one pawn exchange and all pieces were on the board. In game 79 there was a minor piece exchange on the king side, evals slowly increased. The black queen moved forward on the queen side, came back, moved forward on the king side and came back again. On move 30 Stockfish created a pawn majority on the queen side. Leela doubled rooks on the half open g file, Stockfish doubled rooks on the c file, opened the b file and created a passer.

Leela moved a bishop to c6 to disconnect the rooks from the c4 passer. Stockfish moved a rook forward on the b file to support the pawn, the engines exchanged a pair of rooks. Stockfish gave a rook for the blocking bishop and a pawn, still holding on to its passer. The game reached a QRN vs QBN position, Leela captured the black passer and Stockfish created two new passers. On move 61 queens were exchanged. 

Leela captured the two black passers on the queen side, Stockfish managed to regain a pawn after exchanging knights but the game ended in a tablebase win.

In game 80 the engines exchanged bishops in the center and opened the c file. More minor pieces were exchanged and Stockfish captured a pawn. Evals increased, Leela doubled rooks on the c file and Stockfish pushed pawns in the center. On move 28 Stockfish gave a knight for a pawn and created connected passers in the center. 

Leela captured a pawn on the queen side, Stockfish pushed the e4 pawn, after exchanging queens Stockish had 3 connected passers in the center. Leela lost a rook for a passer, it captured the other two  passers and Stockfish saw the win in its PV. The game reached a R vs N ending, black with two pawns up. The white king moved forward and Stockfish captured pawns, the game ended in a tablebase win. There were two white wins in this pair, Stockfish leads 27-16.

Season 27 superfinal games 61-70

After 70 games Stockfish leads 23-12 with 35 draws. Stockfish won two game pairs and its lead is 11 wins. Leela hasn't won a game pair in the last 16 pairs, and there are only 15 pairs left in the match.

Games 61-62 started with a sideline in the Queen's gambit accepted, central variation. Black was up a pawn with a passer in the center. In game 61 Leela exchanged both its bishops for knights causing two black doubled pawns. Leela captured the black passer, both queens moved forward and then were exchanged. The game reached a RN vs RB position, Stockfish's eval came down while Leela remained stable. The engines shuffled for a long with a few pawn moves, after move 88 the started to exchange pawns and pieces and Leela's eval came down enough for adjudication. In game 62 Stockfish exchanged minor pieces and captured the passer. After more exchanges the game reached a QRN vs QRB position on move 18. Evals came down, another series of exchanges reduced to a rook ending with white a pawn up. Evals were low enough for the draw rule and the game was adjudicated. 

Games 63-64 started with a rare sideline in the French Tarrasch, pawn center variation. The center was locked, all pieces and pawns were on the board. In game 63 Leela pushed pawns on the king side and castled short, Stockfish pushed pawns on the queen side and opened the b file. The engines exchanged a pair of rooks and Stockfish castled short as well. Evals were stable as the engines mostly shuffled, for a few moves Leela's eval increased above 1.5. Stockfish captured a pawn and created a passer on the queen side, Leela's eval came back down. Leela opened the king side, Stockfish gave a knight for two pawns and exchanged queens.

The engines shuffled again for a while with stable evals, Leela moved a rook to the 7th rank. On move 52 the engines traded minor pieces, evals started to increase. Stockfish pushed a passer to h3, then gave a rook for a bishop and reduced to a RNN vs BB position with black 3 pawns up. 

Stockfish pushed a second passer to a3, Leela blocked with a knight, then exchanged the other knight for a bishop. Stockfish captured a pawn on the king side and pushed its passers there to g3 and h2 but there the white king blocked them. Leela gradually captured pawns and the game ended in a tablebase win.

In game 64 again Stockfish pushed pawns on the king side and Leela pushed pawns on the queen side, the piece moves were a little different and evals increased early. Stockfish castled short and the engines exchanged a pair of rooks. The black queen moved forward on the b file, Leela captured a pawn and created an advanced passer. Stockfish pushed the f pawn, Leela gave a knight for the pawn to keep the king side closed.

Stockfish moved major pieces to the a file and Leela castled its king. Leela lost the passer and traded queen for a rook and knight. Leela captured a pawn and created another passer on the queen side, it tried to block the opening in the pawn wall with its remaining pieces. On move 45 the engines exchanged a pair of bishops and the game reached a QNN vs RBN position. 

Leela couldn't hold the block on the queen side, after a series of exchanges the engines reduced to a knight vs pawns endgame. The white king moved forward and captured pawns, Stockfish queened a passer and mated. There were two white wins in this pair, Stockfish leads 21-12.

Games 65-66 started with a 22-ply sideline in the Nimzo-Indian defense, Saemisch variation. The engines castled in opposite directions, all pawns were on the board and there was one minor piece exchange. In game 65 the engines played behind their pawn lines and blocked the queen side. There was a pawn exchange in the center and another on the king side, Leela gave a pawn and opened the e file. Stockfish's eval came down, the major pieces moved to the king side and a minor piece exchange opened the f file. The engines exchanged queens and Leela's eval came down as well. The exchanges continued and the game was adjudicated on move 45. In game 66 Stockfish thought for 45 minutes on its second move. The engines blocked the queen side and exchanged minor pieces on the king side. Leela captured a pawn on the queen side and created a passer, Stockfish locked the center and exchanged bishops. Stockfish regained the pawn, it avoided a queen exchange for a few moves but then agreed. In a RRN vs RRN position the engines started to shuffle, Stockfish's eval came down while Leela's eval was not low enough for the draw rule. The engines exchanged knights, the game was adjudicated on move 99. 

Games 67-68 started with a sideline in the Ruy Lopez exchange, Bronstein variation. The engines castled in opposite directions, all pawns were on the board and there was one minor piece exchange. In game 67 Stockfish thought for 45 minutes on its first move, which was not what Leela expected. There was one pawn exchange on the king side, Leela pushed pawns on the queen side and a pawn exchange opened the b file. In a series of exchanges the queens were off, evals slowly came down. The pawns stabilized and the game reached a RRN vs RRB position. There was a long shuffle, the game was adjudicated on move 85 after a series of exchanges.

In game 68 Leela played the first move it expected in game 67. Stockfish pushed pawns on the queen side, there was a minor piece exchange on the king side. Evals started to increase, a pawn exchange opened the d file, Stockfish moved its queen forward on the queen side and captured a pawn. The black king felt the danger and walked to the king side. The white queen retreated, a pawn exchange opened the b file, Leela regained the pawn and the game reached a RBN vs RBN position. Stockfish pushed a passer to a7 and Leela blocked with the rook. 

Stockfish moved pieces forward on the queen side while the black king walked back there, Stockfish captured a pawn, Leela replaced the rook with its king as a blocker on a8. Leela pushed the c passer until it reached c2 and the white king blocked it. In a series of exchanges most pieces were off as well as the two passers and only knights remained. Stockfish was up a pawn, it captured a second pawn and the game ended in a tablebase win. Stockfish wins the game pair, it leads 22-12.

Games 69-70 started with a 22-ply rare sideline in the Sicilian Najdorf variation played in human chess. There was one pawn exchange, all pieces were on the board, white castled long and the black king was uncastled. In game 69 the engines exchanged a pair of knights, Stockfish threatened the white king on the queen side and kept its king in the center. On move 21 evals dropped, Stockfish opened the center and the black queen moved forward. Leela countered and forced the black king to move, after a series of exchanges the game reached a RR vs Q ending. Both kings were exposed, evals were low and the game was adjudicated.

In game 70 after exchanging knights Leela did not threaten the white king immediately. Stockfish captured the g7 pawn with its queen and Leela captured the g2 with a rook, the engines exchanged a pair of rooks. Leela moved its other rook, so there was no option of castling the king.

Stockfish moved a rook to the open g file, its eval started to increase. Stockfish opened the center with a pawn exchange, the white queen moved to the king side as well. The black king felt in danger and Leela moved it to the queen side. The engines opened the queen side and after a series of exchanges the game reached a QN vs QN position. Stockfish's eval was close to 4 while Leela's eval was still low. 

The black queen moved to capture the white h passer. This exposed the black king to attacks, Stockfish gave many repeating checks and captured the a pawn. On move 82 Stockfish managed to get its knight to d6, by this time Leela's eval was already increasing. Stockfish saw the win in its PV, it avoided a queen exchange, Leela lost material and the game ended in mate. Stockfish wins the game pair, it leads 23-12.

Season 27 superfinal games 51-60

After 60 games Stockfish leads 20-11 with 29 draws. Stockfish won 3 more game pairs and extended its lead to 9 wins. There were two more game pairs with two white wins in the last 5 pairs. Leela hasn't won a game pair in the last 11, since there are only 20 game pairs left in the match it is safe to assume that Stockfish is going to win.

Games 51-52 started with the Queen's pawn game, Krause variation. The c file was open, the black queen was out on the queen side and the black king side pieces were not developed. In game 51 both engines developed their pieces and castled their kings. The engines played out a long PV agreement, Leela gave a pawn and opened the e file, then its queen moved forward and captured a pawn on the queen side. Leela's eval jumped for a few moves and came back down. The engines exchanged a pair of rooks and Leela captured another pawn on the queen side, creating connected passers. The game reached a RN vs RB position, Stockfish's eval was at 0 but Leela's eval wouldn't come down. Stockfish captured one passer, the other reached the 6th rank. Leela saw the draw and the game was adjudicated.

In game 52 the engines developed their pieces and castled but with some changes compared to game 51. The engines traded bishops, Leela captured a pawn on the queen side and created a pawn majority, while Stockfish captured a pawn on the king side and weakened the black king's pawn support. Leela moved rooks to the g file to protect its king, the engines mostly shuffled for a while with stable evals. Stockfish pushed the d pawn and it became a passer. Evals started to increase after move 47, Leela pushed pawns on the queen side and Stockfish pushed the passer to d6.

Stockfish captured one pawn on the queen side, the game reached a QRR vs QRR position and the engines cleared the queen side pawns. Leela captured a pawn on the king side and equalized material, the engines exchanged queens and each had two pawns left. Stockfish managed to move its rooks to the open h file with its passer unharmed. It chased the black king forward to the center and captured a pawn, it saw the win in its PV.

Stockfish moved its rooks to the 6th rank, then pushed the passer forward. Leela exchanged rooks and the game ended in a tablebase win. Stockfish wins the game pair, it leads 16-9.

Games 53-54 started with a 20-ply line in the Vienna game, Anderssen defense. There was one pawn exchange on the king side, black pushed pawns on the queen side, all pieces were on the board and both kings were still uncastled. In game 53 there was one minor piece exchange and the engines castled in opposite directions. Another minor piece exchange locked the queen side, Stockfish had a bishop pair but with so many pawns the white knights were better. The engines shuffled for a while, they locked the king side and shuffled some more. On move 47 Leela captured a pawn on the queen side and created a passer, Stockfish moved a bishop forward and used it to complete a pawn wall. There was a very long shuffle and evals drifted down, on move 104 Leela opened the a file and the engines started to exchange pieces. The game wad adjudicated a few moves later.

In game 54 the engines exchanged minor pieces and opened the e file, then castled in opposite directions. Leela's eval was quite low, around 0.5, while Stockfish eval increased. Stockfish gave a bishop for a pawn and captured a rook for a knight, on move 26 its eval jumped over 3 while Leela's eval was still under 1. 

Leela's eval finally reacted, Stockfish gave a rook for a knight and attacked the black king. The engines played out a long PV agreement, the game reached a QR vs QR position and the center pawns were cleared. Stockfish's pieces controlled the center, on move 43 Stockfish captured the a pawn and exchanged rooks. 

Leela avoided exchanging queens, Stockfish used this to keep the black queen away and slowly pushed the a passer. Leela captured a pawn but Stockfish queened the passer and mated. Stockfish wins the game pair, it leads 17-9.

Games 55-56 started with a sideline in the Nimzo-Indian defense, Saemisch accelerated variation. All pawns were on the board, there was one minor piece exchange, all white pieces were undeveloped. In game 55 the engines exchanged pawns in the center and a pair of bishops, the white king moved without castling. Stockfish castled its king, Leela did the same by moving the rook and the king. Leela's eval started to increase, it created a passer in the center and pushed the h pawn. Most of the black pieces were passive, Leela slowly prepared its king side attack.

On move 40 Leela checked with its knight on g6, Stockfish exchanged knights and a white pawn landed on g6. Stockfish captured a pawn while Leela pushed the passer to e7. Leela drove the black queen away, Stockfish in desperation preferred to take the passer and gave its queen. Leela gave some material back and found a quick way to mate.

In game 56 the engines repeated game 55 for 14 plys with transposition, the white king moved without castling after exchanging bishops. The engines castled exactly as before, Stockfish created a passer in the center and pushed it to the 6th rank, its eval increasing. Stockfish gave a pawn on the king side, Leela refused two offers of another pawn to keep the g file safe, as a result it pushed a pawn to g3 without support.

After exchanging minor pieces Stockfish moved a rook forward and captured the g3 pawn. Leela could take the h5 knight but avoided opening the g file. Stockfish doubled rooks on the g file, then captured a rook for a knight. Leela captured the white passer while the white queen moved forward on the king side. Stockfish shifted its rooks to the e file and exchanged queens. 

Stockfish used the fact that the black pieces couldn't move without losing material, it pushed pawns on the king side and forced the king to move. The engines reduced to a rook vs pawns endgame, Leela was 4 pawns up but they were no match for the white rook. The game ended in a tablebase win. There were two white wins in this pair, Stockfish leads 18-10.

Games 57-58 started with a 26-ply sideline in the Ruy Lopez, closed, Flohr system, rare in human chess. All pieces and pawns were on the board. In game 57 Leela locked the center, a pawn exchange opened the b file. Leela captured a pawn and the engines mostly shuffled for a while. Stockfish regained the pawn and the first piece exchange was on move 36. Evals started to come down, the engines exchanged pieces and the game reached a QRR vs QRB position with black a pawn up. The engines continued to exchange pieces and pawns and the game was adjudicated.

In game 58 Stockfish locked the center like in game 57, this time a pawn exchange on the queen side created a passer for Leela and the b file remained closed. Evals started to increase, on move 31 a few exchanges on the queen side created a white passer in the center and opened the a file where Stockfish had doubled rooks. 

Leela gave a pawn, a minor piece exchange opened the h file. Stockfish gave a rook for a bishop and pawn and the black king was exposed. The game reached a QRB vs QRR position with white two pawns up on move 48.

The engines exchanged a pair of rooks and traded pawns, Stockfish captured another pawn and created a second passer on the queen side. It pushed the d passer to d7 where Leela captured it and Stockfish captured the g pawn, creating a passer on the king side. After exchanging queens Leela lost its last pawn, Stockfish queened a passer and the game ended in a tablebase win. Stockfish wins the game pair, it leads 19-10.

Games 59-60 started with a 22-ply line in the KID Fianchetto variation, played in high level human chess. The center was locked and all pieces and pawns were on the board. In game 59 evals increased steadily from the start. There was one minor piece exchange on the king side, then Leela doubled rooks on the b file and exchanged knights and pawns there. The a file opened, Stockfish also doubled rooks on the b file to protect its b6 pawn. After another minor piece exchange Leela had more attackers and it captured the b6 pawn. In a series of exchanges Leela gave a pawn and the engines reduced to a RB vs RB position. 

Leela captured the c pawn and focused on its d passer. Stockfish moved its rook to the 2nd rank to control the white king as a counter. Stockfish captured a pawn on the king side, then moved its rook to the d file so the white passer will not move. This let the white king move forward to support the passer. Stockfish captured two pawns while Leela pushed the passer to d7. Stockfish gave the rook for a bishop,  Leela was on time to stop any black passer and the game ended in a tablebase win. 

In game 60 all pieces stayed on the board, there was one pawn exchange on the queen side that let the black queen side rook have some room to move. All the rooks moved to the a file and the engines shuffled for a while. For a few moves Leela's eval dropped, then it came back again, Stockfish's eval increased slowly. Stockfish cleared the 2nd rank and moved its rooks to the king side, on move 41 it exchanged pawns and opened the g file. The engines exchanged a pair of rooks and minor pieces, the h file opened and both kings were exposed.

The black pieces were passive, defending the black king and pawns and each other. Leela moved the knight on the queen side to join the defense, after Stockfish gave a pawn its bishop moved forward and landed on e6. Leela tried to counter with a passer on the queen side, with the black queen supporting. Stockfish gave a rook for a knight and attacked the black king, which ran to the queen side. Leela lost more material and was mated. There were two white wins in this pair, Stockfish leads 20-11.

Season 27 superfinal games 41-50

After 50 games Stockfish leads 15-9 with 26 draws. Stockfish won two more game pairs, it has a comfortable lead at the half way point of the match. There were two more pairs with two white wins.

Games 41-42 started with an 18-ply sideline in the Alekhine defense, modern Flohr variation. The engines exchanged a pair of minor pieces and opened the d file, the black king was still in the center. In game 41 both engines developed their pieces and Stockfish castled. There was a pawn exchange on the king side, then Stockfish gave a pawn on the queen side and exchanged a pair of knights. Stockfish's eval came down, it created a passer in the center through a bishop exchange. The game reached a RRB vs RRN position, Leela also created a passer but its eval came down and the engines shuffled. The engines traded pawns, the game was adjudicated after a pair of rooks was exchanged.

In game 42 the engines repeated game 41 for 19 plys with a transposition. Stockfish's eval started to increase, there was a pawn exchange on the king side like before and Stockfish pushed pawns on the king side. Leela's eval increased as well, on the queen side there was a series of exchanges that opened files and most minor pieces were gone. 

Stockfish moved a rook to the back rank and forced the black king forward. The white major pieces moved to the e file attacking the knight on e7. Stockfish gave a pawn on the king side and its king found safety behind a black pawn. It gave another pawn and exposed the black king, seeing a win in its PV.

Stockfish traded RR for QN, it captured two pawns and the white king moved forward. Leela lost more material and the game ended in a tablebase win. Stockfish wins the game pair, it leads 12-7.

Games 43-44 started with a 22-ply line in the Catalan open defense. There was a Q vs RB imbalance with black a pawn up and the black king was still uncastled. In game 43 Leela regained the pawn and Stockfish castled its king. Evals increased as the engines shuffled for a while, on move 26 there was a series of exchanges and the engines reduced to a Q vs RB position.

The engines exchanged a pair of pawns on the king side and the white king moved forward. Stockfish pushed the e pawn and it became a passer. Leela attacked the black king with its queen, it pinned and captured the bishop.

The white queen blocked the black passer, Stockfish protected it with its rook. The black king supported its queen side pawn, this let Leela use its pawn majority on the king side to create a passer. The game ended in a tablebase win.

In game 44 Stockfish regained the pawn and Leela castled its king as in game 43. Evals increased steadily, the engines exchanged knights, there were pawn moves but no exchanges. On move 40 Stockfish gave a rook for a bishop and pawn, then captured another pawn and the game reached a Q vs RR position with white two pawns up. 

Stockfish exchanged pawns and created a passer in the center, then it captured a pawn and created connected passers on the queen side. The white king moved forward on the king side and captured another pawn, Stockfish saw the win in its PV. The engines cleared the king side pawns completely, there were 3 white pawns left. Stockfish pushed a passer to the 7th rank, Leela lost material and the game ended in a tablebase win. There were two white wins in this pair, Stockfish leads 13-8.

Games 45-46 started with a sideline of the Sicilian, Scheveningen, Keres attack variation. There was one pair of pawns exchanged and all pieces were on the board. In game 45 Leela pushed pawns on the king side, the engines castled in opposite directions. The engines exchanged pieces on the queen side and evals came down. Stockfish pushed the d pawn and it became a passer, the engines locked both the king side and the queen side. The game reached a RRB vs RRB position, Leela captured the black passer and exchanged a pair of rooks. The game was adjudicated when evals were low enough for the draw rule. 

In game 46 Stockfish pushed pawns on the king side but the engines didn't castle right away. Stockfish's eval increased, it exchanged minor pieces on the queen side and blocked the center with a knight. On move 17 Leela thought for 17 minutes and its eval jumped, both engines castled long as Stockfish threatened to open the king side. There was a pawn exchange the weakened the center, Stockfish had two bishops aiming at the black king and the pieces around it.

Stockfish exchanged knights and opened the d file. The black king moved to b8 to get away but that led to a discovered queen skewer. Stockfish gave a rook for a bishop, then a series of exchanges reduce to a queen ending with white two pawns up. 

Stockfish had a passer on the 7th rank, Leela used checks and repetition to capture the passer. Now Stockfish used checks to get its king forward while keeping its pawns safe. The white king side pawns moved forward and Stockfish created another passer on the 7th rank. The queens were exchanged and the game ended in a tablebase win. Stockfish wins the game pair, it leads 14-8.

Games 47-48 started with the French Winawer, advance variation played in high level human chess. In game 47 Stockfish pushed pawns on the queen side, then exchanged pawns and knights in the center. Stockfish captured a pawn and exchanged minors on the king side, opening the h file for the white king side rook. Leela castled long and Stockfish moved its king without castling. On move 20 Stockfish thought for 31 minutes and its eval jumped, though Leela's eval stayed around 1. Leela developed the rook through the h file and moved it to the center, doubling rooks on the d file. A pawn exchange opened the h file and Leela regained the pawn and opened the d file. Leela captured another pawn, the black king was starting to feel trapped with major white pieces threatening it from both sides.

Stockfish regained the pawn and opened the g file, it kept the d file blocked with a rook. Leela moved its major pieces to the f file and Stockfish had to defend the f7 pawn as well. The black king became more exposed, on move 57 Leela exchanged rooks and reduced to a QRB vs QRN position.

Leela threatened mate and captured two pawns, then it drove the black king forward on the queen side. Stockfish lost material and the game ended in a tablebase win.

In game 48 Stockfish thought for 41 minutes on its first move, and then Leela played a move that wasn't in its PV. The engines exchanged pawns in the center, then in a long PV agreement Stockfish gave a knight for two pawns and opened the d file. The black king moved without castling and Stockfish castled long. Stockfish gave a rook for a bishop, its attack on the black king compensated for the lost material. The black king ran forward to the queen side, Stockfish gained material and the game reached a RBN vs RRN position with white two pawns up. 

Stockfish's eval increased while Leela's eval was stable for a long time. Stockfish captured the e pawn and the engines exchanged knights. Leela moved its rooks forward and captured a pawn back on the king side. Leela gave a pawn to break the white pawn structure on the queen side, Stockfish pushed a passer to a6 where it was protected by the bishop. The white king moved forward, after move 54 Leela's eval started to react. On move 61 a pair of rooks was exchanged.

Stockfish pushed the c passer forward and Leela couldn't stop the two white passers. Stockfish queened twice and mated. There were two white wins in this pair, Stockfish leads 15-9.

Games 49-50 started with an 18-ply sideline of the KID orthodox variation played in human chess. The center was locked, both kings castled and all pieces and pawns were on the board. In game 49 the engines pushed pawns on the king side, a pawn exchange opened the e file and both engines created a passer on the f file. Evals came down quickly, the engines exchanged minor pieces and a pair of rooks, then Leela gave a rook for a bishop and its passer moved to the e file. The exchanges continued and the game was adjudicated on move 41. In game 50 the engines exchanged a pair of pawns in the center, then Stockfish pushed pawns on the queen side and opened the a file. Evals came down as the engines exchanged minor pieces and a pair of rooks, the game reached a QRN vs QRN position. Stockfish opened the h file and the game was adjudicated after the engines exchanged rooks. 

Season 27 superfinal games 31-40

After 40 games Stockfish leads 11-7 with 22 draws. Leela won a game pair and reduced the gap to 4. In game 31 Leela had a promising position but Stockfish managed to hold the draw. In game 34 Stockfish had a spectacular win with piece sacrifices and a king side attack that Leela didn't see coming, Stockfish had a winning PV on move 27. Game 40 was a slow Stockfish win in an open board, again it took Leela a long time to see it couldn't hold. After 15 game pairs with no double white wins there were 3 in the next 5. 

Games 31-32 started with an 18-ply line in the KID Fianchetto, Simagin variation, played in high level human chess. All pieces and pawns were on the board at the start. In game 31 the engines exchanged a pair of pawns on the queen side, a few minor pieces and a pair of rooks. After move 24 evals slowly increased, the engines mostly shuffled and Leela pushed pawns on the king side. Stockfish had less than a minute left on the clock, it used a knight to block the queen side. Leela's eval was over 2 for a few moves and came back down. The engines locked the king side and reduced to a QRN vs QRB position. Stockfish's eval came down as the engines shuffled. On move 95 Leela gave a pawn, its eval also came down. After exchanging rooks the game was adjudicated on move 114. In game 32 Stockfish gave a rook for a bishop but captured a pawn on the queen side and created a passer. Leela's eval slowly came down, Stockfish pushed pawns on the king side and there was one pawn exchange on move 31. There was a long shuffle, on move 78 the engines exchanged minor pieces and then Leela gave back the rook for a bishop. The engines continued to shuffle and Stockfish's eval came down as well. After move 100 evals jumped back a little, the game reached a QRB vs QRN position and the king side opened. Leela went a pawn up but evals came down slowly again, Stockfish regained the pawn but could only shuffle. A series of exchanges reduced to a Q vs R ending, both evals were low and the game was adjudicated on move 167.

Games 33-34 started with a sideline in the Pirc defense, Austrian attack, dragon formation. In game 33 Leela pushed pawns on the king side, after Stockfish castled it moved pieces to the king side to attack the black king. Stockfish captured a pawn in the center, yet evals increased quickly. Stockfish surrounded its king with pieces, with no room to move. The engines exchanged pieces and the game reached a QRB vs QRN position.

The black knight was trapped by its own pawns, while Stockfish tried to get it out safely Leela exchanged queens and regained the pawn. Both engines captured pawns until most of the board was cleared. Leela was up a pawn with connected passers on the king side. 

Strockfish couldn't hold on to its pawn, Leela captured it and slowly pushed the passers forward. Stockfish lost the knight for a passer and the game ended in a tablebase win.

In game 34 the engines exchanged a pair of pawns on the queen side, Stockfish moved its queen forward on the king side and Leela captured a pawn, weakening its king safety. Stockfish's eval increased rapidly while Leela thought it was safe. Leela captured two more pawns in the center while the white queen was on h6. On move 21 Stockfish moved its queen side rook to a3, so it could quickly join the attack on the king side. This was not what Leela expected.

Leela's eval started to jump, but too late. Stockfish traded its queen side rook for a knight and moved its two knights forward to join the attack, it already saw a win in its PV. On top of everything Stockfish sacrificed its second rook, temporarily it was down 2 rooks for a knight.

Stockfish chased the black king all the way to the queen side, capturing the black queen for a knight in the process. Leela lost more material and couldn't prevent mate. There were two white wins in this pair, Stockfish leads 9-4.

Games 35-36 started with an 18-ply sideline of the Slav defense, Steiner variation. In game 35 the engines exchanged minor pieces on the queen side. Evals increased a little and then stayed stable for a while, the engines opened the e file with rooks facing each other but did not exchange them. On move 31 Leela captured a pawn.

Leela blocked the e file with a bishop, evals jumped when Leela pushed pawns on the king side. The white king moved forward to support the pawns. Stockfish had to deal with multiple threats to its king and its pieces, on move 47 it gave a rook and countered with an attack on the white king. The king side opened and the white king was exposed, Stockfish also had the white QR in a skewer, but it was down a rook and evals were high in Leela's favor.

Stockfish chose not to take the rook, that would result in a RB vs R ending. Leela gave two pawns on the queen side and the queen moved forward. Stockfish lost more material and was mated. 

In game 36 the engines repeated game 35 for 13 plys with a transposition. The engines exchanged a pair of pawns on the queen side, Leela used a bishop to block the files there. Evals were low and mostly stable, the engines mostly shuffled behind their pawns. After move 30 evals started to increase very slowly, on move 54 Stockfish had less than a minute on the clock when it decided it was time to push pawns on the king side.

Stockfish opened the h file and the d file, its queen moved forward to the center of the board and it attacked the black king with a rook through the h file. Leela exchanged queens and captured a pawn, Stockfish created a passer in the center. Stockfish pushed the passer to d6 with bishop support, then doubled rooks on the h file.

Stockfish gave the passer but threatened mate, Leela had to give material to let its king escape to the center. The game reached a RRB vs RB position, the white king moved forward and the game ended in mate. There were two white wins in this pair, Stockfish leads 10-5.

Games 37-38 started with a sideline of the Benoni defense, Hromodka variation. The center was locked and all pieces and pawns were on the board. In game 37 the engines played behind their pawn lines, both engines castled long and seemed to be shuffling with low and stable evals. On move 36 there was a pawn exchange on the king side, then a minor piece exchange on the queen side and evals started to increase. Another pawn exchange on move 46 opened the f file and Leela created a passer in the center. Stockfish pushed the h pawn and created a passer, Leela's eval jumped as all rooks moved to the f file and Leela blocked it with a knight.

There was a long shuffle, the white king moved to the king side. Leela changed its mind on whether to place the king to the right or left of the open f file, in the end the king stayed on g1. Leela moved the knight on f5 and replaced it with a rook. Stockfish captured the rook for a knight, Leela gave another pawn and its second rook moved forward on the f file. The white queen moved to f5, in a series of exchanges Leela traded its rook for two minor pieces. 

Stockfish protected its pieces from the white queen, Leela captured two pawns. In desperation Stockfish gave a rook and attacked the white king. When Leela found safety for its king it pushed a passer and queened. Stockfish delayed with checks but was mated. 

In game 38 Leela castled short and Stockfish kept its king in the center. Stockfish gave a pawn on the king side, clearing the h file for its king side rook. Evals came down, the white king walked to the king side and Stockfish placed a bishop on h6, then supported it with a pawn on g5. Leela created a passer in the center and pushed it to the 3rd rank. Leela gave a bishop and then captured a rook for a knight. In a series of exchanges Stockfish captured the passer, queens and a pair of rooks were exchanged. Leela reduced to a bishop vs pawns ending, but the white bishop was trapped and the black pawns stopped the white king advance forward. Stockfish could only shuffle and it lowered its eval slowly, the game was adjudicated 20 moves later. Leela wins the game pair, Stockfish leads 10-6.

Games 39-40 started with an 18-ply sideline in the Zukertort, kingside Fianchetto variation. All pieces and pawns were on the board. In game 39 the engines exchanged a pair of pawns on the king side, Stockfish kept its king in the center. Stockfish pushed the e pawn that became a passer, after move 21 evals increased a little. The engines opened the b file and exchanged a few minor pieces, Stockfish's eval came down and then jumped up when it realized that it hadn't planned on Leela's move 28. 

Leela captured a pawn on the queen side and created a passer. Stockfish regained the pawn, Leela offered to exchange queens but Stockfish refused to created another advanced passer on the queen side. The black king walked forward to the king side away from the white major pieces. Leela captured a rook and gave a bishop, the game reached a QRR vs QRN position. Leela captured a pawn and created a second passer on the queen side, Stockfish managed to capture both. All pawns were cleared on the queen side. 

Leela captured the black passer, its pieces moved forward to attack the black king. The white king was exposed but found safety on the h file. Leela exchanged queens and gained material, the game ended in a tablebase win. 

In game 40 the engines repeated game 39 for 13 plys. Leela kept its king in the center but on move 23 it castled short. The engines started to play out a long PV agreement that started with a series of exchanges. Evals came down and the board opened, Leela had a passer in the center while Stockfish had connected passers on the king side. The black king was completely exposed and in danger with so many pieces still on the board.

Leela refused to take the white rook for a bishop, a white bishop pair would be very strong in this position. Leela surrounded its king with pieces, the engines traded pawns until each had two left, white on the king side and black on the queen side. The engines seemed to shuffle but Stockfish's eval slowly increased. The engines exchanged a pair of bishops and Leela pushed its pawns, its eval stayed under 1. Stockfish secured its king, attacked with its queen and rook from one side or the other. On move 84 Leela's eval was still around 1, Stockfish's eval over 3.5.

At this stage Leela's eval jumped, it saw it was unable to hold the position. The white queen and rook continued their attacks until on move 96 Stockfish captured a pawn and the queens were exchanged. Stockfish captured the remaining black pawn, then started to push its pawns forward. The game ended in a tablebase win. There were two white wins in this game pair, Stockfish leads 11-7.