Season 14 premier division after RR5

Crosstable after RR5


After 2 clean RRs KomodoMCTS crashed for a third time and was disqualified. It keeps playing but the results of all its games in the division will be ignored. As a result the actual crosstable is not as it appears in the live and archive sites. After 5 RRs the standings are: 

Stockfish +12, Leela +3, Komodo +2, Houdini +2, Fire -4, Ethereal -7, Andscacs -8.

Stockfish is still unbeaten in the division and will qualify for the superfinal. Leela, Komodo and Houdini are fighting for the second spot with Leela 0.5 point ahead. Leela lost twice in this RR, its worst RR so far in the division. This allowed Komodo and Houdini to get close and now the race is very close and every game counts.

KomodoMCTS was disqualified and it will be relegated back to division 1. The other engine to be relegated is one of Ethereal and Andscacs. Fire is still in danger but has a comfortable gap of 2 points from last place. Ethereal has no wins in the division yet it is 0.5 points ahead. The engine that loses less games will survive.

Leela suffered 3 losses in 4 games, including one from the previous RR. This led to a check of the GPU hardware and it was found that there was a problem with the GPU fan setting. However this problem probably started from division 3, recall that Leela won 3 divisions convinvingly and it is close to reaching the superfinal in the premier division. As a result the organizers decided against replaying any games.

There were a few one-sided openings in this RR, the reverse games should be exciting to watch.

A few interesting games

Stockfish - KomodoMCTS: Stockfish had an eval advantage of about 1 from the start, and it gradually increased. The black pawn line was mostly on the 6th and 7th ranks, leaving very little room for the pieces to move. Stockfish attacked on the king side, KomodoMCTS surrounded its king with pieces so that it was vulnerable to knight threats. In a series of exchanges Stockfish won a bishop for pawns, later KomodoMCTS lost a knight to avoid mate and the game was adjudicated.


Komodo - Leela: See featured game below.

KomodoMCTS - Ethereal: KomodoMCTS had an eval over 1 despite being a pawn down. KomodoMCTS regained the pawn and the engines exchanged down to a double rook ending. Ethereal's pawn structure was weak, KomodoMCTS captured a pawn and created a majority on the king side. Then it exchanged a pair of rooks and captured a pawn on the queen side, leading to a won rook ending.

Leela - Houdini: Leela's eval was over 1 and increasing from the start. It had a pawn majority on the queen side that later became a passer on the 7th rank. Houdini gave a rook for a bishop to get rid of the passer and the game reached a RB vs BB position. Leela's eval peaked over 4 while Houdini's eval remained below 1. Leela tried hard but couldn't break Houdini's defenses, the game ended in a draw.

Stockfish - Komodo: After a series of early exchanges Stockfish was up a pawn and had an eval over 1.5. The engines played out a long PV agreement that ended in a RB vs R position, Komodo two pawns up. It took Stockfish a while to convert the win. After a few pawn exchanges the white rook got behind the black pawns and started to attack them. The game was adjudicated before Stockfish started to push passers on the king side.

Komodo - KomodoMCTS: KomodoMCTS went a pawn up after several early exchanges, Komodo's eval was over 1 and increasing. In another series of exchanges Komodo won a knight and the game reduced to a RN vs R ending. KomodoMCTS saw it was losing and it gave up, letting Komodo capture its pawns and rook.

Fire - Leela: Fire had an eval advantage from the start, Leela's eval jumped over 2 very early while Fire's eval was below 1. Material was equal and the engines exchanged pieces, Fire went a pawn up only on move 30, Leela's eval was already over 7 at this stage. The game reached a knight ending and the pawns raced forward. Leela promoted first but Fire promoted with a check and had a second pawn on the 7th rank. Leela could give a few checks but this only delayed the adjudication.

Stockfish - Andscacs: Stockfish had an eval advantage from the start, its eval remained under 1 for the first 35 moves. Andscacs captured a pawn and the position opened up, Stockfish's eval jumped over 2. The black king was vulnerable to attack, Andscacs was busy protecting it and Stockfish used this to capture black pawns. The game reached a RN vs RB position with Stockfish 2 pawns up and the game was adjudicated after several more moves.

Featured game: Komodo - Leela
Premier division, round 29
Link to game on TCEC

Evals were close to 0 at the start of the game, even after Leela went a pawn up. The engines castled in opposite directions, Komodo moved its pieces to the queen side facing the black king and evals started to increase.


Leela offered a rook for a bishop for a few moves and its eval jumped oveer 1.5. Komodo waited for the right moment to take the offer, then the engines reduced to a QR vs QN position and Komodo's eval jumped over 2.



Both queens captured pawns, Leela cleared the king side and Komodo cleared the queen side. Komodo's eval slowly increased but Leela thought it was much safer than before. Leela's pawns had a head start but Komodo's king side pawns had a clear path, Komodo also had a rook on the back rank for protection. Leela was late in realizing it was heading for a loss.



Komodo's h pawn ran fast and queened. Leela also queened a pawn but lost one queen for the white rook. In the end Komodo had two queens to Leela's one, it was close to mate when the game was adjudicated.

Season 14 premier division after RR4

Crosstable after RR4


Stockfish remains in the lead with a +3 score in this RR. Leela had a great RR with 4 wins, and despite losing a game to Stockfish (first loss in the division) it extends the gap to 1 point from 3rd place. Komodo and Houdini are still in the race, they need wins and/or luck to overtake Leela.
KomodoMCTS continues to survive and not crash. Ethereal scored -4 in the RR and drops to the bottom of the table joining Andscacs. Fire is 1 point ahead of the relegation zone and is not in the clear yet.

A few interesting games

Andscacs - Houdini: Houdini's eval was negative from the start. Andscacs opened a file on the queen side and placed a rook on the 7th rank, Houdini sacrificed a knight for pawns and created a pair of connected passers. The engines exchanged pieces and Andscacs gave back the knight to remove one of the passers. This left a double bishop ending with Houdini a pawn up. The white king walked to the queen side to stop the passer, the black king captured a pawn on the king side and secured the win for Houdini.

Stockfish - Houdini: Stockfish's eval was close to 1 from the start. Houdini pushed pawns on the king side, leaving its king without pawn support. Stockfish pushed pawns on the queen side, all pawns remained on the board until move 33 when Stockfish opened the queen side. Evals were over 2, Houdini opened the king side and created a little space for its pieces, exposing the king to attacks. Stockfish gave a rook for a bishop, but with all its pieces targeting the black king Houdini could not hold. The game was adjudicated with PVs showing how Stockfish can reduce to a winning endgame.

Leela - Fire: Leela's eval was over 1 and increasing from the start. Fire opened a file on the queen side and controlled it with major pieces, Leela covered its back ranks and did not allow Fire to attack from there. Meanwhile the black pawns blocked one of Fire's bishops, and Leela pushed pawns on the king side and trapped the second bishop in the corner. Fire was paralyzed, though it took a while to recognize it was losing. Leela had all the time in the world first to exchange queens and then to walk with the king to the queen side and drive away the black rook. In despair Fire gave a bishop to break the blockade, a white passer forced Fire to lose more material and the game.

Ethereal - Leela: Leela's eval was negative from the start, it kept its king in the center and blockaded the center and king side with pawns, its eval gradually increased. A pawn exchange opened a hole on the queen side, the black king walked to safety on the king side and Leela moved pieces to the queen side. Another pawn exchange created a queen side passer for Leela and Ethereal's eval started to increase as well. Leela pushed the passer to the 3rd rank and slowly increased the pressure, until Ethereal gave a rook for a knight to capture the passer. Leela reduced to a winning R vs B ending.

Komodo - Fire: After several early exchanges queens were off, Komodo had a bishop pair advantage and an eval over 1. Fire reduced to an opposite color bishop ending with Komodo a pawn up. The white king was better placed than the black king, allowing Komodo to capture a second pawn. Komodo was able to convert this advantage to a win.

Stockfish - Ethereal: Stockfish's eval was over 1 a few moves after book though material was equal. As the board cleared up it became evident that Ethereal's pawn structure was weak. Stockfish focused on the backward d6 pawn and Ethereal put both rooks behind it to defend. In a RRN vs RRN position the h6 pawn became a second target. Ethereal's pieces were not fast enough to defend both pawns and Stockfish captured the h6 pawn. The game reduced to a knight ending, Stockfish captured a second pawn and the game was adjudicated.

Leela - Andscacs: Andscacs pushed its king side pawns in front of a castled king. Leela kept its king in the center, then pushed a pawn to h6 with its eval jumping over 2.5. Leela attacked the king side pawns and weakened their structure, Andscacs remained calm and was sure in its defense. Leela's king walked to the queen side, its eval increasing though it seemed Andscacs was holding. The game reached a RN vs RB position, it took Leela a long time to find a winning path. It captured a pawn and reduced to a winning rook ending. A double win for Leela for this opening.

Leela - KomodoMCTS: Leela had an eval around 1 from the start. The engines opened the queen side, KomodoMCTS had an isolated pawn in the center. Leela's eval jumped over 4 when it exchanged a bishop for a knight and created a pawn majority on the king side. The engines shuffled for a long time, Leela reduced to a RN vs RB position on move 78. It delayed the king side push to move 104, this created a passer that cost KomodoMCTS a bishop and the game was adjudicated.

Ethereal - Komodo: Ethereal started with a small eval advantage, Komodo equalized and evals came down to 0 despite Ethereal being a pawn up. The engines exchanged down to  QRB vs QRN position, but one move before adjudication by draw rule evals became negative. Ethereal exchanged queens and Komodo regained the pawn, evals stayed below 1. Ethereal pushed a pawn and queened it, giving its other pieces and leaving a Q vs RN position Komodo 2 pawns up. Evals remained low for a while, then Ethereal blundered and evals jumped. Komodo connected its pawns and its king, surrounded by its pieces. Two connected passers started to march and the game was adjudicated.

Houdini - Ethereal: Houdini had an eval advantage that gradually increased. There were almost no exchanges in the first 40 moves, Houdini's eval was over 3 as it increased the pressure on the queen side pawns in a closed position. The black pieces were busy defending the queen side, when Houdini opened the king side it won a knight and Ethereal's defense collapsed. The game was adjudicated before Ethereal lost more material.

Stockfish - Leela: See featured game below. First loss to Leela in the division.


Featured game: Stockfish - Leela
Premier division, round 28
Link to game on TCEC

Stockfish had a small eval advantage from the start, but it remained around 0.5 for the first 30 moves. Both kings were safe, there was one open file on the queen side that Leela controlled, the engines gradually exchanged pieces. On move 33 Stockfish offered a pawn but did not expect Leela to take. When Leela calmly took the pawn Stockfish's eval jumped over 2.


The PV showed that Leela saw the immediate tactic, it was losing a rook for a knight and pawns. However, it thought it had a perpetual check draw and missed Stockfish's 38.Bxb5 move. When it saw what happened Leela's eval jumped over 3. After several check moves the engines reduced to a QR vs QN position.


Stockfish captured the black b pawn and the pawn on the a file became a dangerous passer, though it was still far away from promoting. Leela countered with central passers of its own, Stockfish attacked the back ranks and threatened mate.


Leela's last resort was checks against the white king. The black queen chased the white king for more than 15 moves, while evals continued to increase. The game was adjudicated when the king approached the a8 corner, the support of the white pieces guaranteed a stop to the checks and a win for Stockfish.

Season 14 premier division after RR3

Crosstable after RR3

Stockfish continues to lead the table, it added two wins in the RR and has a +8 score, 2.5 points ahead of the competition. Leela is now in second place and is the second engine without loss. Komodo and Houdini are 0.5 a point behind, recall that Komodo benefited from two crashes.
KomodoMCTS limited the number of threads to 32 and hasn't crashed in this RR. With a +1 score this RR it is moving away from the relegation zone, one more crash and it is out though.
Andscacs won its first game of the RR, but with 3 losses it is at the bottom of the table and likely to be relegated. Ethereal is the only engine without a win, and with a -2 score in the RR it is tied with Fire in joint 7th place.

A few interesting games

KomodoMCTS - Ethereal: KomodoMCTS pushed pawns on the queen side and in the center, giving it a space advantage. Ethereal's eval started to increase on move 23 and it began to shuffle on the back rank, as if it was just waiting without any plan. Meanwhile KomodoMCTS created a 3 vs 1 pawn advantage and an advanced passer on the queen side. Ethereal gave a rook for a bishop, evals over 2. It took KomodoMCTS a while to convert the win, the game was adjudicated in a QRB vs QR position.


Stockfish - Komodo: See featured game below.

Ethereal - Andscacs: Ethereal had an eval advantage from the start, then it created a R vs BB imbalance and evals came down to 0. After exchanging queens evals became negative, Ethereal had a passer that got as far as the 6th rank and was stopped. The game reached a R vs BN position, Andscacs had a double passer on the queen side that Ethereal couldn't stop. First win for Andscacs in the division.

KomodoMCTS - Andscacs: Andscacs grabbed a pawn and allowed KomodoMCTS to develop a rook on the queen side. KomodoMCTS gave another pawn and created an advanced passer in the center, then regained the pawns and exposed the black king. Evals increased as KomodoMCTS attacked on the king side, Andscacs gave a rook for a bishop and the game reached a RRN vs RBN position. Andscacs had an advanced passer that was worth some material, but KomodoMCTS reduced to a winning tablebase 3P vs B position.

Houdini - KomodoMCTS: KomodoMCTS kept its king in the center. It allowed Houdini to open the king side as it captured a rook for a knight, and evals went over 1. The black king had to run to the queen side, it was still exposed and Houdini won back material. The engines reduced to a RBN vs RR position, the white pieces coordinated well to defend the king. The game was adjudicated when Houdini pushed a passer to the 6th rank.

Andscacs - Leela: The game reached a RBN vs QN position on move 26 with evals at 0. Leela pushed pawns on the king side and its eval became negative and jumped to 2. Then it gave two pawns on the king side and captured two pawns on the queen side, creating a passer there. After exchanging knights it took Leela a while but it found a way to convert.

Stockfish - Andscacs: Stockfish's eval was over 1 after a few moves in a wild opening. The game reached a QR vs QR position, at the right moment Stockfish exchanged queens and won a pawn. Then it exchanged rooks to get a winning king and pawns ending.


Featured game: Stockfish - Komodo
Premier division, round 16
Link to game on TCEC

The game started in a closed position, there were almost no exchanges in the first 20 moves and evals remained close to 0. On move 21 Stockfish locked the center with pawns, its eval increasing a little.


Most of the black pieces were on the queen side and Stockfish gradually moved its pieces to the king side. Stockfish's eval climbed higher as the tension grew, reaching over 4. When it was ready to attack Stockfish opened the king side with its pawns, but reacting to Komodo's moves it then won a bishop on the queen side instead.


The black king was still under threat along the open g file. Komodo kept its king surrounded by pieces and pawns, it made sure the king was safe but allowed Stockfish to push a pawn to the 7th rank.


The advanced passer cost Komodo a rook and the game.

Season 14 premier division after RR2

Crosstable after RR2


Stockfish is leading after a +2 score in the RR. Komodo, Leela and Houdini are in the fight for 2nd place. Komodo enjoyed a second crash result, without the crashes it would be in third place. Leela won two games in the RR, its first wins in the division. Houdini lost a game to Stockfish, its first loss.
At the bottom of the table there are 4 engines fighting against relegation. KomodoMCTS is playing well when it is not crashing, however with two crashes so far there is a real possibility it will be disqualified. Fire had a disappointing RR with a -3 score, it will probably lose its status of the last few seasons as the 4th best engine.

A few interesting games

Stockfish - Houdini: Stockfish had a small eval advantage, there were almost no exchanges in the first 32 moves. Stockfish went a pawn up with eval over 1, though Houdini had a passer that had to be blocked. After a few exchanges and some shuffling Houdini pushed a pawn on the king side and evals started to increase. Stockfish pushed its queen side pawns and then reduced to a N vs B ending.The game was adjudicated and the PV showed how Stockfish can capture black pawns and win.


Leela - Fire: See featured game below.

Komodo - Fire: Queens and knights were off early. Komodo's eval started to increase while it offered a rook for a bishop. Fire did not accept at first, when it took the exchange it gave it back and only RB vs RB were left. Komodo's eval stayed around 2 for a while, then it jumped over 6 as Komodo's king advanced and with a bishop sacrifice Komodo created a central passer on the 7th rank. Fire kept playing, it gave back the bishop and captured the passer. However the rook ending two pawns up was a win for Komodo. Komodo's first win that wasn't a crash.

Leela - Andscacs: Leela had an eval over 1 after the position opened up. The engines exchanged pieces until only RB vs BN remained, Andscacs two pawns up. The bishops were of opposite colors, Andscacs placed its pawns so the white bishop couldn't attack them, its pieces in a fortress. The engines shuffled for a long while, then captured pawns until only one black pawn was left. Andscacs blundered the 7 man position, without tablebase support, it lost its pawn and the game was adjudicated as a tablebase win. It should be noted that the winning sequence was over 60 moves long, with a capture after 49 moves, almost a cursed win.

Andscacs - Stockfish: Andscacs gave a rook for a knight and created a central passer. Evals were close to 0 for over 30 moves, then Stockfish took over. It managed to reduce to a B vs R ending, the rook was strong behind the white pawns and the bishop could not defend them all. The game was adjucated as Andscacs was about to lose all its pawns.

KomodoMCTS - Fire: Evals were low for the first 30 moves. The position was open, Fire had a central passer and KomodoMCTS had a pawn majority on the queen side. Evals increased very slowly, then started to jump as the engines exchanged most of the remaining pieces. The game reached a queen ending, KomodoMCTS created a queen side passer while the black king was too exposed and on the other side. Fire couldn't stop the passer and the game was adjudicated.

Featured game: Leela - Fire
Premier division, round 10
Link to game on TCEC

Leela had a small eval advantage from the start. On move 22 Fire created a queen side passer, and it pushed it to the 4th rank but didn't have the support to push it further. Leela had more space on the king side, but Fire's king looked safe enough.


Leela slowly moved pieces to the king side and its eval increased over 1. At the same time Fire focused on the queen side, and it left the black king with only a few defenders. Leela gave a pawn and increased the pressure on the king side, Fire thought it was safe and was slow to respond.


Evals started to jump when Leela opened the king side. Fire realized its king was in danger while too many pieces were on the queen side. Leela gave a knight to move another defender out of the way, the black king was exposed with all the white pieces attacking.


The game was adjudicated before Fire lost material and the PVs showed mate.

Season 14 premier division after RR1

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.

Season 14 division 1 final results

Final crosstable


Ginkgo crashed 4 times in the division and was disqualified. This means that Ginkgo is automatically relegated, and removing its games changes the table somewhat but does not change the promotions and other relegation.

Leela won division 1 convincngly, and KomodoMCTS finished 2nd. These two engines started in the lower divisions this season and both reach the premier division which is the final destination. This means that we will have a NN GPU engine in the premier division for the first time, as well as two Komodo versions playing.

Fritz is relegated together with Ginkgo. Fritz did not win any games in the division. It's a shame that Ginkgo crashed out, it would have been close to 3rd place if it were more stable.

A few interesting games

KomodoMCTS - Fizbo: Fizbo gave a pawn and opened the center, but did not get a strong attack. When Fizbo moved a rook forward KomodoMCTS trapped it. A series of exchanges that included a queen sacrifice and pawn promotion by Fizbo resulted in a QN vs QB position, KomodoMCTS two pawns up. Fizbo got one pawn back but KomodoMCTS reduced to a winning N vs B ending.


Leela - Jonny: Evals increased quickly though material was equal. Leela pushed pawns on the king side, trapping a bishop and keeping the black king in the corner. After reducing to a NN vs BN position Leela captured a pawn. It took Jonny a long time to untangle its king and bishop, Leela exchanged down to a knight ending and captured a second pawn for the win.

Fizbo - Laser: For 35 moves the position was equal, then evals started to jump. Fizbo sacrificed a knight on the king side, then got it back on the queen side and was a pawn up. Only RBB vs RBN remained, Laser lost a knight and tried to eliminate the white pawns. However Fizbo kept one pawn, enough for a win in a BB vs B position.

Jonny - Chiron: Chiron gave a rook for a knight early in the game. Evals increased for a while, Jonny's eval peaked over 2, but then the engines started to shuffle and the evals did not change. The engines reduced to a QR vs QN position and evals climbed again, this time Jonny found a winning path in a queen ending with a pawn up.

Leela - Fizbo: The game reached a bishop ending (same color) on move 32. Leela outplayed Fizbo, despite being a pawn down Leela created two passers and forced the black bishop and king to block them. This left the white king free, enough to win the game.

Fizbo - Jonny: Evals started to increase after Fizbo opened the king side, exposing the black king to attack. Jonny's king was close to being mated, by the time it was safe Fizbo was a pawn up in a RN vs RB position. Fizbo then captured another pawn, and two connected passers secured the win.

Leela - Laser: There were several early exchanges, Leela had a pawn majority on the queen side with a protected knight on c6. After some shuffling the engines exchanged queens and evals resumed their increase. Leela reduced to a won rook ending with 3 pawns up.

Ginkgo - Fizbo: Ginkgo went two pawns up with connected passers on the queen side. The white king stayed in the center and the white king side rook was stuck, but Fizbo could not get an attack going. Fizbo gave another pawn to open the king side, then it gave a rook for a knight, still its counter was too weak. Ginkgo started to push its queen side pawns and the game was adjudicated. Too bad that Ginkgo already crashed 3 times, it is still playing but the games will not be counted in the final crosstable.

With one RR left Leela is leading the table, 1.5 points ahead of KomodoMCTS and 3 points ahead of Fizbo (after removing Ginkgo related points). If the Fritz - Leela game will be replayed the lead will probably increase. It is quite safe to say Leela will win this division and promote. The bottom of the table is also decided after the disappointing crashing out of Ginkgo. Fritz is 2.5 points below Jonny, its only win is a questionable Leela crash. The only open race is for 2nd place between KomodoMCTS and Fizbo.

Fizbo - KomodoMCTS: Fizbo gave a knight for two pawns, opened the king side and exposed the black king. Evals started to increase after Fizbo created a queen side passer, and then it captured two more pawns and created passers in the center. Fizbo sacrificed a rook to promote one of the pawns to a queen in a Q vs RN position, winning after the white king came forward to support. There were two white wins in this opening. With this result Fizbo is only 0.5 points behind.


Fritz - Chiron: The game reached a RB vs RB position on move 27, and seemed to be heading for a draw. 35 moves later Chiron found a way to capture a pawn. Fritz' position collapsed and Chiron won in a slow endgame. A double win for Chiron in this opening.

Laser - Fizbo:  Laser had a small eval advantage from the start, it started to increase after move 30. Laser made threats on the king side while Fizbo's pieces were far from its king, then Laser captured a pawn on the queen side. The king side attack was over with a series of exchanges that left a double rook ending with Laser 2 pawns up, enough for a win. Another opening with two white wins.

KomodoMCTS extends its lead to 1 point after drawing against Leela, 5 rounds to go.

Fizbo - Leela: Fizbo played the openng badly, giving a pawn without real compensation. Leela had a small eval advantage from the start that increased gradually. Leela pushed pawns on the king side and won a rook for a bishop. Fizbo could not hold back the king side attack, it lost more material and the game was adjudicated when it was a rook down. A double win for Leela in this opening.

Fizbo with two losses in a row, KomodoMCTS drew against Chiron and its lead is 1.5 points with 4 rounds to go. Both engines still have a game against Ginkgo which will not count, so really only 3 games left each. Fizbo's chances are very low.

Jonny - Ginkgo: The game reached a RRB vs RRN position on move 19. Ginkgo took over after opening the king side and driving the white king away with its rooks. Eventually Jonny lost a bishop and the game.

Fizbo only managed a draw against Fritz while KomodoMCTS played against Ginkgo. Fizbo is 1 point behind with two games to play, KomodoMCTS has 3 more games.

Chiron - Leela: See featured game below. This was Leela's first and only loss in the division.

Leela - Ginkgo: Leela gave two pawns and developed a king side attack while the black king remained in the center and the black queen was far away. Ginkgo had to walk its king to the queen side, Leela reduced to a double rook ending, it had a pawn advantage and an active king which were enough for a win.

KomodoMCTS - Laser: After a series of exchanges only QN vs RRN remained on move 21. Evals started to increase as KomodoMCTS used its queen side majority to create a passer. Eventually Laser had to lose a rook to stop the passer, losing the game.

Fizbo only drew against Chiron, KomodoMCTS is leading by 1.5 points. Since Fizbo has only one more game to play KomodoMCTS secures 2nd place and promotion to the premier division.

Jonny - Fritz: Jonny outplayed Fritz in a QRB vs QRB ending.

Laser - Leela: Laser gave a rook for a bishop and pawns, it held the position until move 34. Leela broke through the pawn wall and won a bishop. Laser was up 4 pawns in a QRB vs QB position, but after queens were exchanged Leela's rook picked up the white pawns for a win. A double win for Leela in this opening.

Ginkgo - Chiron: Chiron's queen moved forward and Ginkgo trapped it. Chiron managed to exchange queens, but was a pawn down in a RN vs RB ending with its pieces stuck on the king side. By the time Chiron activated its pieces Ginkgo captured a pawn on the queen side, the game was adjudicated with Ginkgo 3 pawns up.

Leela - Fritz: What a rollercoaster game! The engines started shuffling on move 28, and a few pawn moves extended the shuffle to move 136. At this point Leela opened the queen side with exchanges, and shuffling resumed. Leela started to get optimistic, after 40 moves it broke through the center and created a passer. Fritz gave a rook for a bishop to stop the passer and the game reached a R vs B ending on move 198. Leela's eval reached over 7 and started to crawl back down, it didn't see a way to improve. Leela allowed Fritz to push a passer to the 2nd rank, its bishop protecting two crucial pawns, it seemed Leela had lost its chance of winning. Evals came down close to 0, Leela sacrificed a pawn on move 280 to continue playing, and then evals started to increase again. This time Leela did find a way to capture the passer and get the win, the game was finally adjudicated on move 308.

KomodoMCTS - Jonny: Jonny went for a BB vs R imbalance with a passer on the 3rd rank. When Jonny exchanged queens KomodoMCTS' eval started to increase. Jonny's pieces were passive and KomodoMCTS had a strong bishop pair, KomodoMCTS captured two pawns and exchanged down to a winning BB vs R ending.


Featured game: Chiron - Leela
Division 1, round 25
Link to game on TCEC

Chiron had an eval advantage though it gave 2 pawns early in the game. As compensation it had very strong bishops and a rook on the 7th rank. Leela captured a third pawn, it had 3 passers on the queen side and its queen partially trapped in front.


Chiron captured a bishop and material was seemingly equal. Chiron's eval started to increase, Leela didn't see any danger and it pushed its queen side pawns forward. Chiron seemed to sacrifice a bishop, but it couldn't be taken beacuse of a mate threat. Then Leela saw what was coming and its eval jumped over 2, too late.


The bishop still could not be taken, the f7 pawn is pinned and cannot take the white queen. The black king was in immediate danger and the black queen was hanging. Leela was forced to exchange pieces and lose its queen, reaching a QRN vs RRN position. Chiron had to deal with the black passers on the queen side, Leela fought back by capturing the remaining white pawns. The game reached a QN vs RN ending.


Leela tried to build a fortress, but it couldn't stop the white queen from getting to the back rank. Chiron found a way to drive away the black king and the game was adjudicated.

Season 14 division 1 statistics

A summary statistics table of previous stages and seasons. 

Draw rate, wins

 
Final draw rate was 59.8%.


Game termination

The three most common game termination causes were:
34.8% - TCEC win rule
27.7% - TCEC draw rule
16.1% - SyzygyTB 
16.1% - 3-Fold repetition


Ginkgo crashed 4 times in the division and was disqualified, Fritz crashed once. One Leela game was stopped due to a network failure and was later replayed.

Moves per game


Median= 63.5
Average= 71.0

There were 16 games longer than 100 moves, the longest was 308 moves (Leela - Fritz, round 28, Leela won, longest win in TCEC history).

Time per game (hours)

 
Median= 2:06
Average= 2:03

Openings

There were 6-move book openings in this stage chosen by Cato. The first letter of the ECO codes was distributed as follows:


The 6-move book determined the opening in most cases, 82.1% of the game pairs repeated the same ECO code twice, 76.8% repeated the same opening variant. All of the game pairs repeated the ECO first letter twice.

Reverse pairs, wins


Reverse pairs, same moves 


Pairs of reverse games diverged very quickly, 41.1% diverged immediately out of book, 82.1% of the pairs diverged at most after 1 move. The longest repeated sequence of moves was 15 plys (Leela - Jonny, rounds 1 and 8, Two knights defense, two draws)