After 20 games Stockfish leads 3-0 with 17 draws.
Stockfish is slowly accumulating wins, Komodo has not been able to convert opening advantages into wins yet. I hope to see a Komodo win soon, this will make the match more interesting.
In games 9-10 black was up a knight at the book exit, the black king was exposed and the white pieces were better placed. In game 9 both engines had a 0 zero eval from start to finish. The position opened up and reached an unusual RR vs BBN imbalance. Both kings were under threat and the game ended in a perpetual check draw. Stockfish's (negative) eval jumped to 1 at the start of game 10. At first Stockfish gave the material back, though after several exchanges it was again a bishop up. Komodo used the exposed black king to win some material back, creating a R vs BN imbalance. Stockfish had a central passer that reached the 2nd rank, after exchanging queens only RR vs RBN were left and evals started to come down. Komodo gave a rook for a bishop to remove the black passer. In the R vs RN endgame Komodo was 2 pawns up, and that was enough for a draw.
Both engines stayed behind their pawn lines with very few exchanges in game 11. The position became static on move 38 and then the engines started to shuffle. The 50 move draw was avoided twice by exchanges, the game was adjudicated on move 152. In game 12 the position opened up with a series of exchanges, and the game reached a double rook ending on move 34. Komodo had an advanced passer in the center and evals were close to 1. The passer could not advance beyond the 6th rank and evals came down to 0. The game was adjudicated when all the other pawns were gone.
Komodo was up a pawn early in game 13, Stockfish was ahead in development. Komodo gave the pawn back and its defense was solid. After a series of exchanges only RRN vs RRN remained with evals at 0, the engines agreed on a draw. In game 14 Stockfish held on to its pawn advantage and Komodo had more space. After a few exchages Stockfish built a pawn line across the board and the engines started to shuffle. The game ended in a 50 move draw.
Stockfish was up a pawn early in game 15, its eval was over 1. Komodo took over the open d file with doubled rooks and attacked the white king. After a few exchanges Komodo created a central passer and evals came down to 0. Stockfish gave a rook for a knight to get rid of the passer. The engines exchanged most of the remaining pieces and the game reached a N vs R drawn ending. In game 16 the center was blocked and Komodo had a space advantage. After opening a file on the queen side the engines exchanged all the rooks, and evals came down to 0. The engines continued to exchange pieces until reaching a tablebase draw.
In game 17 Komodo traded its bishops for knights early. Stockfish's eval jumped over 1.5 when Komodo captured a pawn on the queen side, Komodo's pawns there became connected passers but they were also the black king's shield and couldn't advance. Stockfish had strong pawns in the center, and the open position also meant more strength for the white bishop pair.
The engines shuffled for a while, evals started to increase after Stockfish opened the king side. It now had two passers, one in the center and one on the king side. Komodo started to feel the danger.
After exchanging queens Stockfish captured a pawn, another exchange led to a second pawn capture. Stockfish was up 2 pawns in a RRB vs RRN position and Komodo's defense crumbled.
Stockfish reduced to a double rook ending 3 pawns up before the game was adjudicated.
In the reverse game Stockfish kept one of its bishops and castled short while Komodo castled long. Stockfish pushed pawns on the queen side and Komodo was slow in developing a king side attack. Only QRB vs QRB remained on move 29 and evals fell to 0. Komodo attacked the white king but could only get checks, the game soon ended in a draw. Another minimatch win for Stockfish.
In games 19-20 black had holes in the pawn structure on both sides of the board and no safe option for castling, while white castled long. In game 19 Komodo pushed pawns on the queen side and castled short. The queen side opened and Stockfish was busy defending against Komodo's bishop pair. Evals came down to 0, the engines exchanged pieces until QRN vs QRR remained with Stockfish 2 pawns up. The black rooks chased Stockfish's queen and the game was adjudicated a draw. In game 20 Stockfish castled long, and evals quickly fell to 0. Stockfish attacked on the queen side and for a while evals were slightly negative, but nothing came out of it. The engines exchanged pieces until reaching a drawn QR vs QR ending.