Season 26 premier division statistics

A summary statistics table of previous stages and seasons. 

Draw rate, wins

Final draw rate was 59.4%. 

Game termination

The three most common game termination causes were:
51.3% - TCEC draw rule
22.3% - Mate
19.6% - SyzygyTB

There were no crashes in the stage.

Moves per game

Median= 71
Average= 79.0

There were 41 games longer than 100 moves, the longest was 251 moves (Ethereal - RubiChess, game 51, draw). 

Time per game (hours)

Median= 2:05
Average= 2:02

Openings

There were variable length book openings in this stage. The first letter of the ECO codes was distributed as follows: 

The engines had almost no freedom to choose the opening variant, all of the game pairs repeated the same ECO code and the opening variant twice.

Reverse pairs, wins

Reverse pairs, same moves

Pairs of reverse games diverged less quickly than usual, 19.6% diverged immediately out of book, 48.2% of the pairs diverged at most after 1 move. The longest repeated sequence of moves was 25 plys (Stoofvlees - RubiChess, games 139 and 167, Vienna Frankenstein-Dracula variation, RubiChess won as white) 

Season 26 premier division, after RR6

Standings after RR6

Stockfish is leading in front of Leela, it won 5 game pairs in the third DRR and Leela only 4. Surprisingly Stockfish drew against Stoofvlees for the second time. KomodoDragon got close to Berserk after beating it in their direct match for the first time. Berserk won the previous two matches. Both Berserk and KomodoDragon had a weak DRR with only 1 game pair win against other lower ranking engines. 

Interesting games

game 116, KomodoDragon - Ethereal: The engines castled in opposite directions, KomodoDragon pushed pawns on the king side and placed a pawn on h6. Ethereal tried to attack on the queen side, the engines traded a rook for two minors and then exchanged queens. Ethereal had 3 connected passers on the king side, in a series of exchanges the engines reduced to a BN vs R position and KomodoDragon created connected passers on the queen side. KomodoDragon managed to block the black passers, the engines traded one pair of passers but Ethereal couldn't stop the remaining white pawns. KomodoDragon queened and mated.

game 117, Stockfish - Ethereal: The center was blocked, Ethereal pushed pawns on the king side and Stockfish thought that was a bad idea. Stockfish gave a pawn and a rook for a bishop, then used threats on the black king and queen to equalize and reduce to a RBN vs RBN position. Stockfish's pieces were better, it captured a pawn and the exchanged down to a knight ending. Stockfish captued more pawns and created passers, then queened and mated.

game 118, Stoofvlees - KomodoDragon: The center was blocked, there were a few exchanges after the start and both kings walked to the king side without castling. Stoofvlees created a passer on the king side, the pawns stablized and the engines shuffled for a long time. On move 57 KomodoDragon let Stoofvlees push the passer, after a minor piece exchange Stoofvlees pushed it to h7. After another long shuffle Stoofvlees attacked from the king side. It lost its passer and the game reached a RB vs RN position but its pieces and pawns were much netter. Stoofvlees captured a pawn and trapped the black knight, KomodoDragon lost more material and the game ended in a tablebase win.

game 120, Leela - RubiChess: There were a few pawn and minor piece exchanges after the start, both engines castled long. Leela's eval was high although the engines seemed to shuffle for a while. RubiChess pushed the h pawn, it became a passer but then Leela captured it and exchanged a pair of rooks. The white king walked to the king side, then Leela gave a knight for 3 pawns and reduced to a RB vs RBN position. Leela pushed a passer forward, RubiChess exchanged pieces but couldn't stop the passer. Leela queened and mated.

game 123, KomodoDragon - Berserk: The engines castled in opposite directions, all pieces were on the board and the d file was open. KomodoDragon pushed pawns on the king side, after move 22 the engines exchanged a few pieces. Berserk captured a pawn and exchanged queens, giving KomodoDragon a passer on the queen side in a RBN vs RNN position. KomodoDragon managed to get the pawn back, Berserk captured the passer but KomodoDragon created another. The game reached a rook ending, KomodoDragon pushed the passer with its king supporting. Berserk couldn't prevent a queening, the game ended in a tablebase win. 

game 130, KomodoDragon - RubiChess: KomodoDragon was up a pawn from the start with a passer on g7. RubiChess equalized material and captured the passer, KomodoDragon created another and pushed it to h7. RubiChess attacked the white king and for a while thought that was enough as a counter. KomodoDragon kept its exposed king safe and captured a knight for a pawn. RubiChess captured the white passer, KomodoDragon captured more pawns and created another passer on the king side. The game reached a RN vs R position, KomodoDragon protected its last pawn and reduced to a tablebase win.

game 132, Stoofvlees - Berserk: The center was blocked and the engines opened the c file, Stoofvlees went a pawn up and created a passer on the queen side. Without any exchanges Stoofvlees slowly moved all its pieces to the king side, then started to exchange pawns and pieces from move 39. Berserk captured the passer on the queen side, Stoofvlees gave a knight for pawns to expose the black king and create passers on the king side. Stoofvlees captured back a knight and was two pawns up in a RRB vs RRB position. It pushed passers on the king side, Berserk lost material and the game ended in a tablebase win. 

game 133, Stockfish - Berserk: The engines castled in opposite directions and gradually exchanged pieces. The game reached a QRB vs QRB position, Berserk had a passer in the center but the black king was exposed. Stockfish used checks to capture a pawn and create a passer on the king side. Stockfish used a queen exchange to create another passer, Berserk captured one but the other was on the 7th rank. Berserk lost material and the game reached a tablebase win.

game 137, KomodoDragon - Stockfish: See featured game below.

Standings after RR5: Stockfish +12, Leela +11, KomodoDragon +1, Berserk 0, Seer -3, Ethereal -5, RubiChess -7, Stoofvlees -9. Stockfish has a small lead at top, it only drew as white against Stoofvlees  and won as black (with bias) against KomodoDragon. Leela drew as black (with bias) against Berserk and drew as white against KomodoDragon. KomodoDragon is in third place after gaining 2 full points on Berserk in RR5, including a direct win in their game. Both KomodoDragon and Berserk lost against Stoofvlees this RR. 

game 142, Berserk - RubiChess: There were only a few exchanges after the start, the engines exchanged a pair of bishops and then traded a pair of pawns, Berserk created a passer on the queen side. Berserk pushed the passer to the 5th rank, RubiChess captured a pawn and exchanged queens. Berserk regained the pawn and reduced to a RNN vs RR position, RubiChess captured the white passer but Berserk had another on the king side. Berserk slowly pushed the passer to the 7th rank, RubiChess lost a rook for the passer and the game ended in a tablebase win.

game 143, Stoofvlees - Seer: Stoofvlees gave a knight for 3 pawns and cleared the queen side black pawns. Stoofvlees captured another pawn but then evals turned negative as the engines reduced to a R vs RB ending with 4 white pawns and 1 black. Stoovlees chose the wrong king move and Seer pushed its pawn forward faster than the white pawns. Stoofvlees lost its rook for the pawn and the black pieces were on time to stop the white pawns. The game ended in a tablebase win. 

game 144, Ethereal - KomodoDragon: The engines castled in opposite directions, Ethereal pushed pawns on the king side, gave a pawn and opened the h file. The white queen moved forward and attacked the black king, in a series of exchanges the queens were exchanged and Ethereal captured a rook for a knight. KomodoDragon captured a pawn and created a doubled passer on the king side ,the engines shuffled and traded pawns for a while. After move 53 Ethereal created connected passers on the queen side, then it managed to trap and capture a knight. The game reached a RRB vs RB position, KomodoDragon lost more material and was mated. There were two white wins in this game pair.

game 149, Stockfish - RubiChess: The engines castled in opposite directions, after exchanging all rooks Stockfish pushed pawns on the king side and opened the h file. The engines exchanged queens and the game reached a BNN vs BNN position with white a pawn up. Both kings moved to the center and the bishops were exchanged, on move 47 Stockfish created a passer on the king side. RubiChess blocked the passer and the white king for a while, after exchanging a pair of knights Stockfish saw the win. RubiChess lost a knight for the passer, Stockfish created another and queened to mate.

game 150, Leela - Seer: There were a few pawn and minor piece exchanges after the start, on move 28 the engines opened the f file. Seer captured a pawn and Leela attacked on the king side. Leela managed to place a protected bishop on d6, Seer gave a rook to capture it and another pawn. The game reached a  RR vs RN position, Seer was two pawns up with a passer in the center. The white pieces were more effective, Leela kept the black king confined on the king side. Leela captured the black passer, then captured two more pawns on the queen side and created a passer. Seer lost its knight, the black king was trapped and the game ended in mate.

game 157, Stockfish - Seer: Seer was up a pawn with a passer on the queen side but its king moved without castling and blocked the king side rook. Seer tried to develop the rook through the h file but it was still restricted and not effective. After some shuffling Seer captured another pawn and connected a passer, while Stockfish placed a rook on the 7th rank. Seer pushed its passers and gave a rook for a knight, after more exchanges the game reached a RR vs R position with black 4 pawns up. Stockfish captured pawns and saw the win, it managed to control the black pawns, eventually it queened and mated.

game 158, RubiChess - KomodoDragon: RubiChess was up a pawn with a passer on g7 from the start. KomodoDragon captured the passer and RubiChess created another on the h file. After exchanging queens the engines traded pawns on the queen side, the game reached a RRN vs RRN position with white two pawns up and with passers on both sides of the board. KomodoDragon captured the passer on the king side but couldn't stop the passer on the queen side. RubiChess queened and mated. There were two white wins in this game pair. 

game 159, Leela - Ethereal: There was one minor piece exchange after the start, all pawns were on the board and both kings remained uncastled. Leela developed its king side rook through the h file, pawn lines blocked the center and queen side with a small hole on the g file. Leela's eval was high though the engines seemed to shuffle. On move 48 Leela opened the g file and exchanged a pair of rooks, after exchanging the remaining rooks Leela created connected passers in the center on move 66. Ethereal lost material for one passer, the game reached a Q vs BB position. Leela gained more material and mated.

game 164, KomodoDragon - Seer: KomodoDragon castled long despite the weak pawn cover there. It then pushed pawns on the king side, giving two pawns and opening the g file. KomodoDragon doubled rooks on the h file, Seer exchanged queens to avoid mate. KomodoDragon captured pawns and moved a its rooks to the 7th rank, Seer exchanged a pair of rooks and the game reached a RN vs RN position with white two pawns up. KomodoDragon slowly pushed connected passers on the queen side, then trapped the black king and mated.

Featured game: KomodoDragon - Stockfish
game 137

The game started with a black bias, Stockfish was a pawn up and the white king moved without castling. KomodoDragon regained the pawn, its king walked to the queen side and trapped the rook there. Stockfish captured a pawn and opened the a file for the white rook the . KomodoDragon tried to create some pressure on the king side with major pieces, Stockfish exchanged a pair of rooks and the game reached a QRB vs QRB position. 

The white king moved to free the rook. The engines shuffled for a while, KomodoDragon's eval remained low but Stockfish's eval increased steadily. On move 54 the engines exchanged rooks, KomodoDragon started to see the problem. Stockfish exchanged pawns on the king side and created a passer. 

The engines traded pawns and Stockfish connected a second passer, KomodoDragon created passers on the queen side but they weren't fast enough. KomodoDragon lost the bishop for one passer and the game ended in a tablebase win. 

Season 26 premier division, after RR4

Standings after RR4

Stockfish and Leela are tied in the lead, both after only 3 game pair wins in the second DRR. Leela closed the gap after beating RubiChess in both games, Stockfish only drew against Stoofvlees after an unexpected loss when playing black. Berserk increased the gap from KomodoDragon after beating it in a game pair for the second time. At the bottom Seer beat Ethereal and is now in 5th place, RubiChess beat Seer but lost more games and dropped to 7th.

Interesting games

game 64, Leela - RubiChess: The black king moved without castling, RubiChess captured a pawn and created a passer on the queen side. Despite this Leela castled long and used the black pawns as shields for its king. RubiChess gave back the pawn and Leela slowly pushed pawns on the king side, driving away the black pieces until it created a passer on g6. After some preparation Leela captured a pawn and attacked from the queen side. RubiChess gave a rook for a bishop and the game reached a QR vs QB position. RubiChess captured the white pawns on the king side but Leela created two passers. After exchanging queens Leela queened a passer and mated.

game 70, Berserk - Ethereal: The engines castled in opposite directions and gradually exchanged pieces and pawns. Berserk traded a rook for a bishop and two pawns, the game reached a QBN vs QRB position and white had 3 connected passers on the queen side. Evals were stable until Ethereal gave a bishop for two pawns on move 51. Berserk still had one passer, after reducing to a BN vs R ending it pushed the passer forward while protecting its other remaining pawn as well. Ethereal couldn't prevent a queening and the game ended in a tablebase win.

game 72, RubiChess - Seer: There were no exchanges after the start, the center was blocked and the engines played behind their pawn lines. RubiChess' eval increased very slowly, on move 40 the first minor pieces wee exchanged. Seer gave a pawn and RubiChess created a passer on the king side, then the pieces shifted to the queen side. More pieces were exchanged and evals increased faster, Seer captured the passer and the game reached a RB vs RB position. The engines traded pawns and RubiChess created more passers. Seer couldn't prevent a queening and mate.

game 74, KomodoDragon - RubiChess: There were no exchanges after the start, the engines formed long pawn lines that blocked the center and king side. After some shuffling the engines exchanged a pair of bishops and opened the a file. KomodoDragon placed all its major pieces on the open file, then in a series of exchanges the engines traded Q for RBN. The white pieces threatened the black king and queen , RubiChess gave its queen for a rook and reduced to a BNN vs N position. RubiChess lost the knight for a passer, KomodoDragon queened another passer and mated.

game 77, Stockfish - Berserk: See featured game below. 

Standings after RR3: Stockfish +8, Leela +7, Berserk +1, KomodoDragon 0, Seer -2, Ethereal RubiChess -3, Stoofvlees -8. This RR had more draws with only 8/28 decisive games. Both Stockfish and Leela drew a game in white against the other engines, though there was a black bias in Stockfish's game against Ethereal.

game 86, Berserk - RubiChess: The engines exchanged most minor pieces and blocked the center. RubiChess opened the king side and Berserk had a passer there. The game reached a RRB vs RRB position and evals started to increase. Berserk captured a pawn, RubiChess created a passer in the center. Berserk gave the passer and created another on the queen side, then exchanged a pair of rooks. The black king was in danger, RubiChess lost its bishop. The black passer was not strong enough and the game ended in mate.

game 92, RubiChess - Leela: Leela castled long even though the white queen had free access to d6. Then it curiously decided that its king should walk all the way back to the king side. Evals came down and the engines shuffled for a long time. On move 62 RubiChess captured a pawn and opened the center. Then in a series of exchanges the engines reduced to a Q vs RRN position with white 3 pawns up. RubiChess quickly captured 2 more pawns, it was 5 pawns up though two pairs were doubled. On move 77 RubiChess pushed a pawn and Leela's (negative) eval started to jump. The white pawns advanced but Leela began to capture them, it was only down two pawns with one black pawn left. Leela pushed its pawn forward and captured two more white pawns, then RubiChess lost its queen and the game ended in a tablebase win. Leela won this game pair from both sides.

game 93, Stockfish - RubiChess: The engines castled in opposite directions and the center was blocked. Stockfish opened the queen side and captured a pawn despite the fact that its king was exposed. Stockfish created a passer on the queen side, then in a series of exchanges RubiChess managed to capture the passer and trade a rook for two minors. RubiChess had a bishop pair but one of the bishops was in trapped in the corner by another white passer. The engines traded pawns and eventually RubiChess gave its trapped bishop for a passer. This created a new passer for white, Stockfish pushed it to the 7th rank and saw the win. RubiChess delayed with checks but eventually lost material and the game ended in a tablebase win.

game 94, Leela - Seer: There were only a few exchanges after the start, Leela pushed pawns forward and had more space. On move 42 Leela gave a pawn and through a series of exchanges created connected passers in the center. Seer had a blocked passer on the king side, after a while Seer gave a pawn and created a passer on the queen side. Leela captured one passer, Seer pushed the other to the 2nd rank and then gave a knight for the two white passers in the center. Leela captured the black passer, after exchanging queens Seer lost more material and was mated.

game 95, Berserk - KomodoDragon: Berserk was a pawn up from the start, there were many exchanges after the start including queens and KomodoDragon regained the pawn. The queen side pawns were mostly cleared, each engine had a passer there. The game reached a RBN vs RNN position, after some shuffling Berserk captured the black passer and KomodoDragon traded bishop for knight. After a long shuffle evals started to increase on move 105. The engines blitzed, Berserk managed to capture a pawn and created connected passers on the king side. KomodoDragon captured the queen side passer, but after the white king came to support the king side pawns were unstoppable. Berserk queened and mated.

game 97, Stoofvlees - Stockfish: Stoofvlees castled long and Stockfish moved its king to the king side without castling. The engines opened the queen side and exchanged queens, Stockfish gave a pawn and created a doubled white passer on the king side. Stockfish hid its king behind a passer and Stoofvlees trapped the king on the h file. The game reached a RBN vs RBN position, Stoofvlees captured pawns and exchanged knights. It was 4 pawns up with no black pawn left, after queening the game ended in a tablebase win. There were two white wins in this game pair.

game 101, Stockfish - Seer: There were only a few exchanges after the start, a pawn exchange opened the b file, then a knight exchange closed it back. Stockfish pushed pawns on the king side, after some shuffling evals started to increase. Stockfish moved a rook forward, the engines traded pawns and Seer created two passers on the queen side. Stockfish had a passer in the center, it captured a pawn and created a passer on the king side. The game reached a RB vs RB position, Stockfish captured more pawns and had a tripled pawn wall on the f file. The black king was trapped and the game ended in mate.

game 110, Seer - Ethereal: Ethereal had an isolated passer in the center, Seer pushed pawns on the king side and moved its king forward. After some shuffling the engines exchanged pieces and reduced to a rook ending with white a pawn up. Ethereal had a passer on the queen side and it moved its king there as support. Ethereal captured two pawns and pushed its passer to the 2nd rank but there it was stopped. Seer created a second passer on the queen side and Ethereal couldn't stop their advance, the game ended in a tablebase win.

Featured game: Stockfish - Berserk
game 77

The white queen moved forward on the king side and the black king moved without castling, trapping the king side rook. Stockfish moved both its rooks to the f file, after move 21 it gave two pawns on the king side while evals increased. 

Berserk managed to free its king side rook, the king side opened with a series of exchanges where Berserk gave a rook for a knight. Stockfish was still two pawns down but with the g file open it limited the black king to the h file.

Both kings were exposed but the black king was under threat. After some preparation Stockfish exchanged a pair of rooks and saw the win in a QRB vs QNN position. Stockfish cleared the king side pawns, Berserk lost material and was mated.

Season 26 premier division, after RR2

Standings after RR2

Stockfish and Leela are leading, Stockfish won all its game pairs against the other 6 engines while Leela won 5/6 game pairs with one draw against Ethereal. They drew their head to head games. So far Stockfish and Leela are in a league of their own, KomodoDragon appears to be out of the top3 that we have seen for several seasons. Berserk is in third place with 3 game pair wins within the bottom 6 engines, KomodoDragon is only 4th with two wins and one loss. Stoofvlees is the only engine without a game pair win, it seems to be the weaker engine of this division.

Interesting games

game 3, Seer - Stoofvlees: In a series of exchanges the engines reduced to a QB vs QB position and Seer went two pawns up. Seer had one passer, after 20 moves of checks and shuffling it pushed the passer. After another 15 moves Seer created a second passer, Stoofvlees gave material and the game ended in a tablebase win.

game 5, Stockfish - Ethereal: There were almost no exchanges after the start, Stockfish pushed pawns on the king side and Ethereal pushed pawns on the queen side. In a series of exchanges on move 23 Stockfish gave a rook and pawn for a bishop, then captured a knight for two pawns. After another series of exchanges the game reached a RBN vs RB position with black two pawns up. Stockfish captured a pawn and attacked the black king, Ethereal exchanged rooks. Stockfish captured two pore pawns and created a passer, the game ended in a tablebase win.

game 8, Leela - RubiChess: Leela managed to trap both black bishops on the back rank in the king side. RubiChess captured pawns and its queen moved forward to attack. Leela surrounded its exposed king with pieces, then in a series of exchanges the engines traded queens and a knight for a rook. Leela captured a trapped bishop, the game reached a RBB vds RB position with black 3 pawns up. Leela captured pawns and promoted a passer to a rook, which RubiChess refused to give a rook for. Leela queened another passer and the game ended in mate.

game 12, Ethereal - Stoofvlees: The engines opened the queen side and Stoofvlees was up a pawn. The black king walked to the king side and the king side rook was trapped. Ethereal doubled rooks on the e file and moved a rook to the 7th rank. The ga,me reached a QRB vs QRB position, Ethereal captured pawns until it was 3 pawns up. The engines reduced to a B vs R ending and the game ended in a tablebase win.

game 13, Stockfish - Stoofvlees: Stoofvlees captured a pawn but it had a disconnected forward bishop. When the black queen moved to protect the bishop Stockfish attacked, it doubled rooks on the d file and moved one rook forward. Stockfish gave a rook for a knight and attacked the exposed black king. Without a material advantage Stockfish used its strength on the light squares to mate.

game 14, Berserk - Ethereal: There were a few exchanges after the start, the engines exchanges minor pieces and opened the a file. The center was blocked and the engines exchanged a pair of rooks. After some shuffling the engines reduced to a QN vs QB position, Berserk captured a pawn and created a passer. Ethereal exchanged minors and delayed with checks but couldn't avoid a queening and mate.

game 15, Leela - KomodoDragon: Leela captured a pawn and created a passer in the center. In a series of exchanges KomodoDragon regained the pawn and opened the queen side. The game reached a RBN vs RBN position, KomodoDragon had a pawn majority on the queen side but Leela blocked the pawns. After exchanging knights KomodoDragon created connected passers, Leela captured a pawn and reduced to a rook ending. Leela gave the rook and queened a passer, the game ended in mate.

game 16, RubiChess - Seer: There were a few exchanges after the start, RubiChess created a central passer after the first pawn exchange. The engines gradually exchanged pieces and pawns, The game reached a RBB vs RBB position. RubiChess pushed pawns on the king side, Seer tried to counter by creating a pawn majority on the queen side. RubiChess exchanged a pair of bishops and captured a pawn, it pushed pawns forward and Seer lost its bishop. The game ended in mate.

game 18, KomodoDragon - RubiChess: The black queen was out early and RubiChess castled long. After exchanging queens RubiChess gave a rook for a bishop and pawn. KomodoDragon moved a rook to the 7th rank and the game reached a RRN vs RNN position. Both white rooks were active, KomodoDragon managed to capture a pawn and create a passer. After exchanging a pair of knights KomodoDragon pushed its passer, it gave a rook for a knight but RubiChess lost its rook for the passer. The game ended in a tablebase win.

game 21, Stockfish - Berserk: There were no exchanges after the start, the engines formed long pawn lines across the board. There was one knight exchange on move 31 and then the engines opened the a file. Stockfish moved all its major pieces to the a file and after some preparation exchanged a pair of rooks. Stockfish was patient, eventually it gave a knight to create a passer. Berserk lost a rook for the passer and the engines reduced to a RB vs BN position. Stockfish created another passer that cost Berserk its knight. The game ended in a tablebase win.

game 22, Leela - Stoofvlees: Leela castled long and both queens moved forward. The white queen captured a pawn on the queen side and Stoofvlees castled short. The engines opened files in the center, then in a series of exchanges reduced to a QN vs QB position. Both kings were exposed, Lela had a passer in the center. Stoofvlees delayed with checks but Leela managed to push its passer and Stoofvlees lost its bishop. Stoofvlees lost more material and the game ended in a tablebase win.

game 23, RubiChess - Ethereal: The engines castled in opposite directions and the center was blocked. After all bishops were exchanged RubiChess opened the f file and Ethereal opened the b file. RubiChess captured a rook for a knight and moved a rook forward on the queen side. RubiChess captured a pawn and created a passer, the game reached a QRN vs QNN position. Ethereal created a passer on the king side, its queen attacked the exposed white king and gave checks. However, eventually RubiChess exchanged most pieces and queened the passer. It was on time to stop the black passer,the game ended in a tablebase win.

game 24, Seer - KomodoDragon: There were many exchanges after the start, the engines opened the queen side and reduced to a RBN vs RNN position with Seer a pawn up. All pawns were on the king side, there was a lot of shuffling and one pawn exchange. On move 67 Seer captured a second pawn and created a passer, then it gave the rook and queened the passer. Seer gave the queen for two knights and reduced to a tablebase win.

game 25, KomodoDragon - Stockfish: KomodoDragon was a pawn up in a closed position, it seemed to have an advantage until it reduced to a RRN vs RRB position. The pawns stabilized and the engines started to shuffle, extending the 50-move counter with pawn moves and captures. The game was adjudicated on move 174. 

game 26, Ethereal - Seer: There were almost no exchanges after the start, except for one minor piece exchange. On move 29 there was a second minor piece exchange, all pawns were on the board and the king side was blocked. Ethereal had a pawn on a6 and it moved a bishop to b7. The white queen moved forward and the engines reduced to a RRN vs RRB position. There was a very long shuffle, only on move 107 Ethereal pushed a pawn to start opening the queen side. Ethereal gave a pawn and created connected passers, Seer lost the bishop for one. Ethereal captured pawns, then Seer gave its rook for the second passer. The game ended in mate.

Standings after RR1: Stockfish Leela +3, Seer Berserk RubiChess 0, KomodoDragon Ethereal -1, Stoofvlees -4. Stockfish and Leela lead together, both won their games as white and drew as black, the only exception was the draw between them with Leela as white. Stoofvlees lost all its games as black and drew as white. The other 5 engines are close to each other and it is too early to say which of them is stronger than the others. KomodoDragon does not currently look like a natural candidate for third place.

game 34, KomodoDragon - Stoofvlees: The white queen moved forward o the king side, the engines opened the queen side and Stoofvlees kept its king in the center. After a series of exchanges the game reached a RBN vs RR position, the engines continued to trade pawns until there was only one white pawn left. KomodoDragon forced a rook exchange and reduced to a tablebase win. 

game 37, Stockfish - RubiChess: Queens were off early and both engines moved their king without castling. Stockfish had a bishop pair advantage while RubiChess had a passer in the center. Stockfish pushed pawns on the king side, for a long time evals increased slowly without an obvious reason on the board. After move 60 Stockfish managed to get a protected pawn to g7 blocked by the black king. Stockfish exchanged minors and gave a pawn to open the f file, trapping the black king. RubiChess lost material and was mated.

game 38, Leela - Seer: There were a few minor piece exchanges after the start, one pawn exchange opened the f file. The engines exchanged a pair of rooks, Leela gave a pawn and created a passer on the queen side. Seer gave a rook for a bishop for the passer, the game reached a QRB vs QBN position. Seer was a pawn up with a passer on the queen side, it seemed to have a fortress on the king side though evals were high. For almost 30 moves nothing happened other than Leela capturing the black passer, on move 65 Leela gave a pawn and threatened the black king. Seer exchanged minor pieces, its fortress was destroyed. After exchanging queens the white king moved forward, Leela created a passer to win.

game 39, Berserk - KomodoDragon: The engines opened the center and exchanged queens early. The engines mostly shuffled for a while, then reduced to a RRB vs RRN position. Berserk moved both rooks to the 7th rank and the white king moved forward. Berserk captured two pawns and created a passer, then reduced to a rook ending. KomodoDragon couldn't avoid a queening, the game ended in a tablebase win.

game 40, Stoofvlees - Ethereal: The engines blocked the center and opened the b file. After a few piece exchanges Stoofvlees created a passer in the center, the game reached a QBN vs QBN position and the engines shuffled for a long time. On move 63 Stoofvlees exchanged bishops, then it captured a pawn and reduced to a queen ending. The white king moved forward and the engines traded pawns, Ethereal equalized material but Stoofvlees had connected passers in the center. Ethereal delayed with checks but the passers slowly advanced, the game ended in a tablebase win. There were two white wins in this game pair.

game 44, Seer - RubiChess: The engines exchanged minor pieces, the first pawn exchange was on move 21 and Seer went a pawn up. The engines shuffled for a while, then RubiChess regained the pawn and after a series of exchanges reduced to a queen ending. Seer had an advanced passer on the queen side, the white king moved forward for support and the black queen blocked. Seer captured a pawn on the king side, it pushed the passer to the 7th rank and captured a second pawn. RubiChess captured the passer but the game ended in a tablebase win. There were two white wins in this game pair.

game 45, Stockfish - Seer: Seer captured a pawn on the king side, after opening the a file Seer chose not to let Stockfish regain the pawn. Stockfish doubled rooks on the a file and exchanged a pair of rooks, after some preparation it cleared most of the queen side. Seer gave two pawns and opened the h file but there was no real threat on the white king. The game reached a RBN vs RBB position, white with an advanced passer on the queen side. Seer lost a bishop for the passer, Stockfish captured the remaining black pawns and mated.

game 48, Berserk - Stoofvlees: The engines castled in opposite directions, Berserk pushed pawns on the king side and Stoofvlees on the queen side. Berserk captured a pawn on the queen side, it protected its king while creating a passer on the king side. Berserk captured another pawn while Stoofvlees tried to attack the b2 pawn, Berserk gave the passer and reduced to a QRN vs QRB position. After exchanging queens Berserk captured another pawn and the game reached a winning rook ending.

game 52, KomodoDragon - Seer: The center was blocked and there was one pawn exchange after the start. The engines blocked the king side and mostly shuffled, the first piece exchange was on move 45. Seer gave a pawn and opened files on both sides of the board, after a series of exchanges the game reached a QRB vs QRB position. After exchanging queens KomodoDragon captured another pawn and the white king moved forward. Seer lost material, KomodoDragon queened and mated. There were two white wins in this game pair. 

game 53, Stockfish - KomodoDragon: The engines castled in opposite directions quite late in the game, after the pawns advanced the kings had less protections. The engines opened files and reduced to a QRB vs QRN position. Stockfish used the exposed black king to force exchanges of queens and rooks. The white king moved forward and Stockfish captured two pawns. KomodoDragon couldn't stop a queening, the game ended in a tablebase win.

game 56, Leela - Berserk: See featured game below. 

Featured game: Leela - Berserk
game 56

The engines castled in opposite directions, Leela had a bishop pair advantage after Berserk traded both its bishops for knights. Leela's eval jumped very quickly, after exchanging queens on move 18 it was already close to 10.

There was a long period with the engines playing behind their pawns lines, Leela pushed pawns and blocked the king side with one pawn on g6 and the black king in the corner. Then Leela opened the a file and exchanged a pair of rooks. 

Berserk moved its king to the center, Leela exchanged minors and captured the b5 pawn, creating a passer. Leela captured two more pawns, in desperation Berserk gave its knight for a passer. The g6 pawn became an unstoppable passer, Leela queened and reduced to a tablebase win.