After 10 games the score is tied 1-1 with 8 draws. According to the explanation of the superfinal openings by Jeroen Noonen (can be found here) the openings are ordered by bias from low to high. The engines disasgreed with this order in the 3rd opening, it turned out to be biased enough for a two white win score.
Evals were essentially 0 the entire game in both games 1-2. In both games white sacrificed a knight for a pawn and black offered its rook. In game 1 Stockfish (as white) did not take the rook and preferred a pawns for knight imbalance. Queens were exchanged early, the engines continued to exchange pieces until reaching a RN vs RNN position on move 23. Leela used its knight to block the white passers on the king side. The engines traded pawns on the queen side, then the white king and rook came forward and ended the game using a mate threat and checks. In game 2 Leela as white accepted the offered rook. Its queen was trapped for a while, by the time it escaped Stockfish was attacking the white king. Leela's rook and bishop on the queen side were stuck, Stockfish exchanged the white pieces that were active and forced a perpetual check draw.
Games 3-4 started with a Q vs BN imbalance. The white king moved forward in game 3, it found safety on the king side but caused difficulty for the king side rook. Leela's eval was slightly negative despite the material disadvantage. Once Stockfish developed its rook through the h file Leela moved its king to the queen side and was focused on blocking files. The engines mainly shuffled for 35 moves, then a file opened on the king side. After exchanging a pair of rooks Stockfish moved a rook forward, then the queen joined the rook while the white king hid behind a black passer. The shuffling resumed, this time evals were low enough for the draw rule. In game 4 Leela opened a file on the queen side and let its king side rook out without trapping it. Leela used the open file to move a rook forward while Stockfish controlled the center with its minor pieces, with two knights hovering near the white king. Leela moved its major pieces forward and Stockfish used the knights to force a perpetual check draw (in the PV when the game was adjudicated).
Games 5-6 started with a 24-ply book in the Nimzo-Indian defense. The engines castled in opposite directions, white gave a rook and two pawns for a knight, white had a pawn on f6 and threatened the black king. Stockfish's eval was over 1 in game 5. Leela captured the pawn on f6 and held off Stockfish's mate threat. Leela felt safe until move 22, after thinking for 8 minutes its eval jumped over 2. Stockfish captured a bishop and the game reached a BB vs R imbalance with black a pawn up.
Evals increased gradually, Stockfish refused to trade a bishop, Leela pushed pawns on the queen side and tried to restrict the movement of the white pieces. Stockfish used its extra piece to threaten pawns and pieces and push Leela back. On move 46 the white rook came forward and captured a pawn on the queen side. Stockfish could have traded its bishop for a rook but delayed this until it traded a pair of rooks. The game reached a BN vs N position.
Stockfish captured the black a pawn and the game soon reached a 6-man tablebase win.
Game 6 started along similar lines, Stockfish captured the pawn on f6 and lost a bishop. From move 19 the engines had long agreements in their PVs and Stockfish's eval came down below 1 while Leela's eval slowly increased. The engines exchanged B for N and the white bishop pair was gone, it seemed Stockfish was holding the reverse. On move 27 Leela forked a rook and queen, still on PV. Stockfish knew how to esacpe, but it thought for 25 minutes before moving. The expected move didn't change but now Stockfish saw trouble ahead and its eval jumped over 2.
The engines continued with their expected moves, Leela almost without thinking. Stockfish's eval continued to increase as it used a lot of time to try to get away from something that bothered it at the end of the PV. After exchanging rooks Leela stopped to think for a while, its eval reacting with a small jump. The engines exchanged queens and the game reached a BN vs R position, which Stockfish was so afraid of with its eval over 4 at this point.
Now Leela took 15 minutes to assess the situation and its eval jumped over 3. It attacked the black pawns on the queen side and captured two while Stockfish tried to keep its rook active on the back rank. Stockfish created a passer on the king side and Leela captured another pawn on the queen side where it had a 3 vs 1 majority.
The black passer was Stockfish's last hope. It needed its king to support passer while it moved forward. By the time the king arrived Leela gave the bishop and queened the e pawn. The material advantage gave Leela the win a few moves later. Two white wins in this opening, score is still tied.
Evals came down quickly in game 7. The engines opened the position and exchanged most pieces, only RRN vs RRN remained on move 34. All rooks were also exchanged, Stockfish had passers on the king side and Leela had passers on the queen side. Both engines were on time to block the passers, the game reached a tablebase draw. In game 8 the position remained closed for a while with only one minor piece exchange until move 20. Evals came down, the engines opened the queen side and reduced to a RRB vs RRB position on move 29. After exchanging a pair of rooks the engines started to shuffle and the game was adjudicated.
The engines castled in opposite directions in game 9. The king side was blocked, Leela pushed pawns on the queen side facing the white king. Evals came down, Stockfish opened the center and a series of exchanged led to a RRN vs RRN position. Leela had a passer in the center, but without pawn moves the draw rule ended the game quickly. In game 10 Leela preferred to castle short, even though its king side pawns advanced and were far from its king. Stockfish opened files on the queen side and gave a rook for a knight and pawn. The black queen moved forward and with a knight sacrifice Stockfish started to give checks with its queen. Leela gave back material and was 3 pawns up for a knight, its king was still exposed. Leela pushed a passer forward and traded its queen for a rook to get the passer to the 7th rank. Stockfish ended the game in perpetual check.
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