Season 14 superfinal, games 31-40

After 40 games the score is even at 6-6 with 28 draws.
There were 10 straight draws, increasing the draw rate to a more normal 70%, still low for a superfinal.

Leela's eval was around 1 after the start of game 31. It castled long and pushed its king side pawns. Stockfish also castled long though the queen side was open. Stockfish's eval came down to 0 after the queens were off, and both kings came forward. After a series of exchanges the game reached a R vs BN ending on move 33. The engines traded pawns until only two white pawns remained, Stockfish was able to hold the draw. In the reverse game the engines opened the king side, Stockfish's eval started below 1 and gradually decreased. The queens were off early, Stockfish castled long and Leela didn't castle at all. Stockfish had a king side passer it couldn't support, after it was gone the engines reduced to a RN vs RB position. It took Leela 35 moves to lower its eval for adjudication.

Games 33-34 started with a long 21-ply book sequence in the King's Indian, Saemich opening. Both games then continued to play the same moves with first divergence on move 19. In game 33 Stockfish's eval dropped to 0, and after a series of exchanges the game reached a double rook ending on move 27. After exchanging a pair of rooks Leela went two pawns up, Stockfish countered with an advanced passer and secured a draw. In game 34 the pieces remained on the board longer. Evals came down to 0 and Leela's eval turned negative, it pushed pawns on the queen side facing the white king. The engines mostly shuffled pieces and then exchanged down to a RR vs RN ending and agreed to a draw.

Games 35-36 were a French Defense variant, a favorite opening for Leela. In game 35 Leela's eval was over 1 and increasing from the start. Stockfish locked the center, Leela was free to operate on the king side and its eval was over 2. The black king walked to the queen side to get away from danger, Leela opened the king side and its eval was close to 3. Stockfish had some counterplay on the queen side but it seemed that Leela was about to win.

Leela perhaps hesitated or wasn't sharp enough, suddenly Stockfish had initiative on the queen side and evals were heading down. Stockfish captured a rook for a bishop, then it gave a second bishop to remove the passer on h6. When the black queen joined the attack on the queen side Leela had to be careful not to get mated, Stockfish's eval came down to 0. Stockfish won a bishop and started to give checks. It took 90 moves to convince Leela it was only getting a draw out of the game.
In game 36 the position was closed and there were almost no exchanges at the start of the game. Stockfish's eval came down to 0 and Leela's eval turned negative again. The engines exchanged pieces gradually, opening the position. The game reached a RB vs RB ending on move 54 and ended in a tablebase draw 50 moves later.

Stockfish's eval was 0 throughout game 37. Both engines castled long and then slowly exchanged pieces. On move 38 only QRN vs QRB remained, on move 53 the knight and bishop were also gone. The game went on until move 121 before draw adjudication. In game 38 Leela kept its king uncastled in the center and built a fortress around it. Evals came down to 0, Leela attacked the white king on the queen side and its eval turned negative. Nothing came out of the attack, evals became positive again when Stockfish created a pair of connected passers on the queen side and exchanged queens. The game reached a BN vs BB position, Stockfish trapped the black LS bishop in the corner and Leela pushed a passer to the 7th rank on the king side. Neither engine could win and after 50 moves the game ended in a draw.

Games 39-40 were a King's Gambit variant. black started both with a significant eval advantage. In game 39 material was equal but Leela's pawn structure was ruined. After exchanging queens evals moved towards 0. Stockfish went a pawn up and created a queen side passer but it was a doubled pawn. The game reached a drawn opposite color bishops ending and continued until move 171. In game 40 queens were off very early, Stockfish's king did not castle and moved forward. Stockfish traded R for BN and was two pawns down, its eval down to 0 on move 19. The game reached a BN vs R ending on move 33. Leela pushed a pair of connected passers on the queen side, Stockfish gave a knight to capture one of them. The game ended in a tablebase draw.