Friday, November 2, 2018

Season 13 superfinal, games 51-58

After 58 games Stockfish leads 7-2 with 49 draws.
Stockfish added two wins, while holding Komodo to a draw in both reverse games.

Stockfish castled long in game 51, then pushed its king side pawns. Komodo kept its king in the center and counter-attacked on the queen side. Evals came down to 0, Komodo felt safe to castle after several exchanges. When a black passer reached the 2nd rank Stockfish hid its king behind it and evals jumped again, but only for a short while. Komodo sacrificed a bishop to expose the white king, and in a QRN vs QR position this was enough for a draw. In game 52 Stockfish castled short immediately and then exchanged pieces in the center. Evals stayed low, Komodo opened the king side and the black king hid behind a white pawn. The engines reduced to a RB vs RB position and the game was adjudicated by the draw rule.

In game 53 Stockfish gave a pawn and trapped a bishop at the start. A series of exchanges led to a BN vs R imbalance on move 22. After exchanging queens the game reached a RBN vs RR position with Komodo a pawn up. Stockfish's eval was close to 1.5, yet the position looked drawish with so little material on the board.

Stockfish won a pawn after exchanging a pair of rooks. Komodo took advantage of the pawn pajority on the queen side, it gave a pawn and created a passer, then pushed it to the 2nd row. The evals started to climb, this may have been a judgment error by Komodo. 

Stockfish blocked the passer with its knight, then traded its a pawn with the black h pawn. This created a pair of connected passers on the king side, and Komodo had to defend against this threat.

Both engines agreed black was losing. Stockfish's king had time to capture the black passer before the game was adjudicated.

In game 54 Komodo attacked through the center with a bishop and knight sacrifice that made the black king move forward. As a result Komodo captured a knight and created a central passer on the 7th rank. In a series of exchanges Stockfish gave back a bishop for the passer, so the total result of Komodo's attack was it being a pawn up in a quiet position. The engines removed all the pawns on the queen side, the game reached a QBN vs QBB position and the engines started to shuffle. The game continued more than 80 moves and ended in a drawn opposite color bishop position. Stockfish extends its lead to 4 points.

Games 55-56 started with black up a knight for pawns and the black king on f7. In game 55 both engines had a passer in the center. Komodo had an eval advantage for a while, a series of exchanges resulted in a BN vs R imbalance and evals dropped to 0. The engines exchanged most pieces, Stockfish gave a rook for a knight to capture the black passer. The remaining pawns vs bishop ending was a draw.
In game 56 Komodo castled long and concentrated forces on the king side facing the black king. Stockfish started with an eval of 1 (negative) which increased to over 2 when it moved its pieces to the queen side. On move 18 the engines started a series of pawn and piece exchanges that cleared the board. Stockfish's advantage in eval and material did not change.

There was only one black pawn left, and Stockfish made sure it was safe. Komodo's bishop pair and rook were not strong enough, Stockfish surrounded its king and pawn with pieces to avoid checks. After a while Stockfish cleared a safe path for its pawn and pushed it forward. 

Komodo could not stop the pawn without losing a piece, the material advantage was enough for Stockfish to win.

Games 57-58 were a Benko Gambit, accepted variant. Both started with white two pawns up and an open queen side for black. In game 57 Stockfish had an eval advantage for a while, Komodo had active pieces on the queen side and white found it difficult to castle its king. After several exchanges Stockfish finally castled, Komodo got the material back by move 22 and evals started to come down. Komodo opened the king side and created a NN vs R imbalance. The white king was exposed and on the run. Stockfish had a passer on the queen side, after exchanging most pieces Komodo forced a draw with perpetual check. In game 58 Komodo castled quickly, the black pieces were concentrated in the center and material was equal on move 19. Komodo captured two pawns and created a pair of connected passers on the queen side, Stockfish countered with a king side attack. A series of exchanges removed all threats and the game reached a QR vs QR position with evals at 0. After exchanging queens the game ended in a drawn rook ending.

No comments:

Post a Comment