After 10 games the score is tied 1-1 with 8 draws. There were two decisive games, a double white win in one opening. One game pair started with a KGA, both games had an explosive start but ended in draws. An explanation of the superfinal openings by Jeroen Noonen can be found here.
In game 1 the engines followed a popular line in a Sicilian Najdorf opening until move 13. Evals were close to 0 though the white king was exposed. Starting from move 21 there was a long PV agreement, Stockfish sacrificed a rook and started to give checks with its queen. The game was close to a repetition when it was adjudicated. In game 2 Stockfish chose a less popular line, evals were close to 0 again. The game reached a RRN vs RRN position on move 20, the engines exchanged pawns and pieces and the game was adjudicated in a drawn rook ending.
The center was blocked in game 3 and the engines stabilized the queen side pawns early. Stockfish opened a file on the king side and exchanged a pair of rooks on move 20, the engines mostly shuffled from then. There were a few pawn moves on the king side and several exchanges of minor pieces, evals came down and the draw rule ended the game in a QR vs QR position. There was a similar setup in game 4, there were fewer exchanges and the engines started to shuffle on move 20. Leela gave a pawn to open the queen side and create a passer, after exchanging queens the game ended in a repetition draw.
Games 5-6 started with a line in the French opening where black had a disadvantage when it retreated the knight to g8 after white played 4. e5. Evals increased slowly after the start of game 5, both kings did not castle and Leela developed its king side rook. By move 25 only two pairs of pawns and a pair of bishops were exchanged on the queen side, Stockfish had a passer but its eval was approaching 2.
The white king walked to safety on the king side and Stockfish finally castled on move 31. Leela captured a pawn on the king side, then captured the queen side passer. The engines reduced to a QRN vs QRB position with white two pawns up.
The engines shuffled for 20 moves, it seemed Leela was waiting for something before pushing pawns on the king side. Evals started to increase again after Stockfish offered to exchange queens.
Leela was more confident without the queens and its king side pawns advanced. Before too long Leela had a passer on the 6th rank and the game was adjudicated before another passer was created. First decisive game of the match.
In game 6 Stockfish's eval was more than 1 from the start. Leela pushed pawns on the queen side and gave a pawn early, causing Stockfish to double pawns but one of these was a valuable passer.
Both kings stayed in the center, Stockfish could develop its king side rook while Leela's rook was stuck. Leela exchanged pieces and regained the pawn, but by the time it opened a path for its rook Stockfish pushed the passer to the 7th rank and only RBN vs RBN remained.
Leela blocked the c passer with its knight and brought its rook to the queen side to cover both white passers. However both engines knew there was no defense.
Leela was able to capture both passers but lost all its pieces, Stockfish was left with a knight and a bishop and the game was adjudicated. Two white wins in this opening, score is still a draw.
Games 7-8 started in the Geller gambit line of the Slav defense, with black up a pawn. In game 7 Stockfish gave the pawn back immediately and created a queen side passer. Evals dropped to 0 though the passer reached the 2nd rank, after a series of exchanges only RRB vs RBB remained on move 24. The draw rule was avoided by pawn moves and captures, Leela captured the black passer and Stockfish pushed another forward. Eventually the pawn moves stopped and the game was adjudicated. Game 8 started similarly, Leela gave a pawn and created a queen side passer. This time Stockfish captured the passer in a series of exchanges and evals came down. Stockfish sacrificed a bishop to expose the black king, then ended the game in perpetual check.
Games 9-10 started with a King's Gambit Accepted. In game 9 Leela gave a knight for a pawn early, Stockfish's (negative) eval increased over 1.5. Leela forced the black king to move, then sacrificed a bishop but attacked a pinned knight. Very suddenly Stockfish realized there was no advantage and its eval dropped, a series of exchanges equalized material and reduce to a RRN vs RRB position on move 21. The engines continued to exchange pieces and pawns, the game ended in a tablebase draw. Game 10 started with a repeat of game 9 for a few moves, then a PV agreement led to an unusual Q vs BNN imbalance on move 14. For a long while evals stayed negative under 1, Stockfish slowly pushed pawns on the queen side and prepared a fortress for its king on the king side. After several exchanges Leela was down to a queen and a rook, the engines started to shuffle and Stockfish's eval came down to 0. Leela opened the king side and the shuffle continued, on move 98 the rooks were exchanged and Leela could only give checks with its queen. Leela wouldn't lower its eval, pawn moves kept the game going until move 213.
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