Crosstable after RR1
Stockfish leads after an outstanding RR with +4 result, Houdini is second with +2. Leela and Komodo have drawn all their games, Komodo's score is +1 due to an opponent crashing.
The bottom of the table is very close, KomodoMCTS, Andscacs and Ethereal with -2 and Fire with -1 (with one win).
KomodoMCTS crashed once in this RR, hopefully this will not happen again. It hasn't crashed before this season, recall that it played in all the divisions.
A few interesting games
Stockfish - KomodoMCTS: Stockfish's eval started to increase when it created a pair of connected passers in the center early in the game. KomodoMCTS captured one of the passers and went a pawn up, by then Stockfish had a strong king side attack and eval close to 2. After several exchanges only QB vs QB were left, with Stockfish a pawn up. Both kings were exposed, Stockfish had two advanced passers, KomodoMCTS gave the bishop and countered with its queen. The game was adjudicated when KomodoMCTS realized it couldn't give checks indefinitely, and then could not avoid a pawn queening.
Houdini - Andscacs: Houdini surprised with its first move after book, retreating its bishop. Andscacs handled the novelty very badly, it moved a bishop 4 times in its first 9 moves while Houdini developed and evals jumped over 2. Houdini blocked the center and opened the black king side. Andscacs lost a knight and pawns, the game was over quickly.
Fire - Ethereal: All bishops were off early, all the pawns remained on the board with evals close to 0. The first pawn exchange was on move 32 as the engines opened a file on the queen side. Ethreal shuffled while Fire slowly infiltrated the queen side. Evals increased as Fire moved its king away and opened the king side. The engines gradually exchanged pieces until only RN vs RN were left. Fire was two pawns up with an advanced passer, Ethereal lost the knight to stop it and Fire won.
Stockfish - Fire: See featured game below.
Ethereal - Stockfish: Ethereal had an eval advantage from the start, but when Ethereal chose to create a R vs BB imbalance evals became negative. After exchanging queens the black bishops were stronger than the white rooks. Ethereal's king was trapped, Stockfish moved its king forward and after exchanging down to a R vs BN position the black king was in a mating net.
Stockfish - Andscacs: Stockfish took over the game after queens were off early. Stockfish pushed pawns on the queen side and had a significant space advantage, though material was equal. With only rooks and knights remaining Stockfish created an advanced passer in the center and placed a rook on the 7th rank. Andscacs gave a rook for a knight and pushed a passer to the 2nd rank, the RRN vs RNN ending was a win for Stockfish.
Houdini - Fire: Houdini was a pawn up in a QRR vs QRR position. Houdini used an open file on the king side to threaten the black king and slowly improve. Evals jumped after the white queen infiltrated the back rank, Houdini created a central passer and the game was over quickly.
Featured game: Stockfish - Fire
Premier division, round 4
Link to game on TCEC
Evals were close to 0 at the start with a small advantage for Stockfish, perhaps because of its bishop pair. Fire pushed pawns on the king side and had a space advantage. Stockfish's eval then jumped over 1.5 after it gave two pawns
on the queen side.
Fire still thought it was fine though its king was exposed and Stockfish dominated the long diagonal with a bishop. Then Stockfish opened a
file on the king side and doubled rooks. Fire countered by pushing a passer to the
2nd rank, Stockfish's eval was already winning.
Fire it realized it was in trouble when Stockfish's queen
joined the rooks and threatened mate. Fire had no choice but to block and exchange pieces, eventually losing material to save its king.
The RB vs R ending was a win for Stockfish after it blocked the passer with its bishop and pushed its f pawn forward.