Season 16 superfinal games 1-10

After 10 games the score is 1-1 with 8 draws. In the premier division Stockfish beat AllieStein 3-0. However AllieStein updated its net and it appears to be better in the superfinal. Hopefully Stockfish will be stable in the superfinal, I wouldn't want crashes to affect the outcome of the match.

Games 1-2 were played without a book start sequence. Game 1 was a French opening, Steinitz variation. Queens were off early and both engines did not castle. AllieStein went a pawn up and the engines started to shuffle in a closed position. The 50-move draw was avoided twice before the engines lowered their evals for adjudication by the draw rule on move 137. Game 2 was a Semi-Slav defense. The engines opened files on the queen side and exchanged most pieces, only QB vs QN were left on move 24. After exchanging queens AllieStein's eval turned negative, the endgame was stopped by a 50-move draw.

Games 3-4 were a King's Indian defense. In game 3 AllieStein broke the diagonal pawn lines and allowed Stockfish to create a passer in the center. The engines mostly shuffled from move 19, evals increased as AllieStein had more space and Stockfish's king was vulnerable.



AllieStein used the open long diagonal for a constant mate threat, then pushed the a pawn forward to the 6th rank. The black pieces were forced to defend passively. 



AllieStein attacked on the king side, Stockfish gave a rook for a bishop and exchanged pieces until only RR vs RN remained.



The material advantage and passer on the 7th rank were enough for a win. First blood in the superfinal for AllieStein.

In game 4 Stockfish kept the diagonal pawn lines and this allowed AllieStein to create pressure on the king side, its eval turned negative. AllieStein opened the king side, Stockfish countered on the queen side and gave a rook for a bishop. after many exchanges the game reached a QBN vs QR position, the king side attack was mostly over and the white king escaped to the center. The game ended in a perpetual check draw. AllieStein wins the first game pair.

Games 5-6 started with a 19-ply book sequence in the Sicilian, Paulsen variation. In game 5
the engines castled in opposite directions, AllileStein pushed pawns on the king side and thought it had an advantage. Stockfish surprised with a rook sacrifice that opened the queen side, forcing a quick perpetual check draw.

Game 6 started similarly, Stockfish pushed a pawn to h6 and caused the long diagonal to open, weakening the black king. AllieStein countered on the queen side but was not able to break Stockfish's defense or to force a perpetual check draw. Stockfish moved a bishop to g7 in front of the black king, its eval increased over 2.

Stockfish opened the f file and threatened immediate mate. AllieStein's pieces were far on the other side, Stockfish traded its queen for a rook and bishop, removing the last defenders. Only RRB vs QR remained, Stockfish's eval jumped over 14.

Black had to use all its pieces to avoid mate on f8. Stockfish created a passer on the queen side and the game was adjudicated, PVs showed that after exchanging all pieces on f8 black can't stop the passer. Stockfish wins a game pair and equalizes.

Queens were off early in game 7 and Stockfish kept its king in the center. After a series of exchanges only RR vs RBN remained, most of the pawns were gone and both kings were exposed. AllieStein's eval stayed over 1.5 for a long time, it created a king side passer and managed to push it forward while Stockfish captured the remaining white pawns. AllieStein sacrificed its rooks and queened the pawn, this led to a drawn Q vs RB ending. In game 8 AlllieStein castled its king and the position remained closed. Evals came down to 0 after files were opened on both sides, the game reached a RN vs RB position and ended in a tablebase draw.

Games 9-10 were a King's Gambit Accepted variant. There were many exchanges after the start of game 9, evals came down to 0 and the game reached a rook ending on move 31. AllieStein thought it had a small advantage, the game continued for 40 moves until it lowered its eval for adjudication by the draw rule. In game 10 the pieces stayed on the board longer, both kings were uncastled in the center and queens were off early. Stockfish's eval was 0, AllieStein thought it had an advantage. The game reached a RBN vs RBN position on move 42, a N vs B ending on move 61, and ended in a tablebase draw.