Season 28 league 1

Final Standings

Integral and PlentyChess advance to the premier division. After twso RRs Integral and PlentyChess had a small lead over Caissa and Reckless. In the third RR Integral opened a small gap ahead of PlentyChess and kept it until the end to win the league. In the 4th RR PlentyChess also left Caissa and Reckless behind, but in the last rounds Reckless got closer until it was only 0.5 points behind. In the end PlentyChess managed to hold on to 2nd place. Integral had 12 game pair wins and one loss to Ceres. PlentyChess had 11 game pair wins and 3 losses, it beat Reckless twice and lost to Caissa twice.

Integral and PlentyChess both started the season in the entrance league, and they made it to the premier division. For Integral this is the first TCEC season, for PlentyChess it is the second one. Reckless is also a new engine for TCEC, it started this season in league 2 and was very close to advancing to the premier division as well. 

Integral and PlentyChess will play in the premier division together with Stockfish, Leela, Berserk, Obsidian, KomodoDragon and Ethereal.

Interesting games

game 10, Viridithas - Stormphrax: Virisithas had a bishop pair advantage, it moved a rook to the 7th rank and the engines traded pawns on the queen side. The engines cleared the queen side and exchanged pieces, Viridithas captured a piece and the game reached a QB vs Q ending. It took Viridithas 20 moves to exchange queens, then it captured pawns, queened passers and won.

game 16, PlentyChess - Viridithas: PlentyChess had a bishop pair advantage, evals increased though the engines seemed to be mostly shuffling. PlentyChess opened a file on the queen side and then exchanged queens. The engines reduced to a RBB vs RNN position, PlentyChess captured a pawn and created a passer. After exchanging a pair of minor pieces PlentyChess captured two more pawns, then queened passers to win.

game 20, RubiChess - Caissa: There were many exchanges after the start, the engines opened the center and exchanged queens. The game reached a RB vs RN position with white a pawn up. After exchanging rooks the engines shuffled for a while, RubiChess gave back the pawn to create a passer. Caissa captured the passer, RubiChess went a pawn up again and created two more passers. Caissa lost the knight for one passer, RubiChess queened the other and mated.

game 30, Ceres - RubiChess: There were almost no exchanges after the start, all knights were gone. Evals jumped after move 33, Ceres gave a pawn on the king side, then captured a rook for a bishop and created a passer. RubiChess tried to attack through the open g file, Ceres gave the passer and exchanged queens. In a RRB vs RBB position Ceres pushed a pawn to h6 and created two more passers. RubiChess couldn't avoid a queening and mate.

game 31, Integral - RubiChess: RubiChess blundered in a QRB vs QBB position, it ignored the danger to its king. Integral used this to capture pawns and reduce to a queen ending 3 pawns up. Integral pushed its passers and queened to win.

game 42, RubiChess - Viridithas: RubiChess captured a pawn early, it had a doubled pawn and Viridithas controlled an open file. The engines exchanged pawns and pieces slowly, the game reached a RBN vs RBB position. RubiChess gave a bishop to create a passer which cost Viridithas a rook. RubiChess gave a rook for a bishop and created an unstoppable passer, followed by mate.

game 44, Reckless - RubiChess: There were a few exchanges after the start and the engines shuffled. RubiChess gave a knight for 3 pawns and it had two connected passers. All rooks were exchanged, evals were stable for a long time. After move 80 evals started to increase, Reckless captured one passer and reduced to a QBN vs QB position. Reckless used the exposed black king to capture all the remaining black pawns, then exchanged pieces and won with its last pawn. 

game 55, Integral - Reckless: Reckless gave a knight for 3 pawns, in a RBN vs RB position the last white pawn became a dangerous passer and Reckless gave the bishop to stop it. After exchanging rooks Integral captured all the black pawns and the game reached a bishop and knight ending on move 85. Incredibly, Integral did not find the win even with tablebase support, on move 113 it became too late and on move 122 Integral finished the game with stalemate. Must be some annoying bug, happened because this season there is no tablebase adjudication.

game 62, Caissa - PlentyChess: The engines castled in opposite directions, Caissa pushed pawns on the king side and PlentyChess placed major pieces on the a file. In a series of exchanges the engines reduced to a RBN vs RBN position. Caissa captured pawns anc created two passers, PlentyChess had one passer but it was not enough. PlentyChess lost more material, Caissa queened and mated.

Standings after RR1: PlentyChess +3, Caissa Reckless +2, Integral Stormphrax +1, Ceres Viridithas 0, Seer RubiChess -1, Revenge rofChade -2, Stoofvlees -3. There are 5 engines with positive scores after one RR. Integral and Reckless are without loss, the other 3 leading engines have one loss each. The gaps are still small and the reverse games can change the rankings. Integral gave away a tablebase win against Reckless, unexpected bug.

game 70, RubiChess - Stormphrax: The game reached a RB vs RB position with white a pawn up. Evals were stable for a long time, the engines cleared the queen side pawns and shuffled for a while. Evals increased after RubiChess gave a pawn and pushed a passer to the 7th rank. Eventually Stormphrax lost the rook for the passer, and mate followed.

game 72, Caissa - Seer: The game reached a RB vs RB position, the engines shuffled for a long time. Evals increased after move 133, the engines exchanged rooks and reduced to a same color bishop ending. Seer had two isolated pawns and the black king was too far to protect them. Caissa managed to capture all the black pawns, then queened a passer to win.

game 74, Seer - Ceres: There were many exchanges on the queen side after the start, the game reached a RRB vs RRN position with white a pawn up and the queen side pawns cleared. Seer created a passer and exchanged a pair of rooks. Seer pushed pawns slowly and carefully, after 30 moves the engines exchanged minors and the white passer was on the 7th rank. Ceres captured the passer and Seer created another, after exchanging rooks Ceres couldn't stop the queening and mate followed.

game 85, Ceres - Integral: There were almost no exchanges after the start, Ceres had a space advantage. A series of exchanges opened the center, Ceres pushed a pawn to h6 and evals started to increase. The engines reduced to a RN vs RN position and Ceres pinned the black knight on the back rank. The white king moved forward, Integral captured pawns but lost the knight. Ceres queened a passer, then gave up material but eventually mated.

game 88, PlentyChess - Reckless: There were a few pawn exchanges after the start, the engines opened the e file. Evals increased slowly, after move 42 the engines exchanged pieces, the queen side opened and PlentyChess was up a rook for a knight and pawn. The game reached a QRB vs QBN position, PlentyChess captured a pawn and Reckless exchanged queens. Reckless tried to avoid more exchanges but PlentyChess captured the bishop, it then queened a passer and mated.

game 94, Reckless - Seer: Reckless gave a pawn to open the d file, then regained the pawn in a series of exchanges. It created a passer on the queen side, Seer gave a rook for a bishop to capture the passer and the game reached a RR vs RB position. The engines cleared the queen side pawns and exchanged a pair of rooks. The white king moved forward, Reckles created a passer and pushed it forward to win.

game 98, Ceres - Viridithas: Ceres had a bishop pair advantage, it gave a pawn and opened the center. After exchanging queens the engines concentrated their pieces in the center, eventually Ceres captured a rook for a bishop and the game reached a RR vs RN position. Ceres made slow progress, after 35 moves it reduced to a 7-man position with only one white pawn left. It took another 40 moves to complete the win.

game 103, Integral - Stormphrax: There were almost no exchanges after the start, evals were stable for a long time. After move 45 evals started to increase, Integral captured a pawn and created a passer on the queen side. Integral pushed the passer to the 6th rank, then it captured another pawn and created a passer on the king side. Stormphrax captured the queen side passer but now the black king was threatened. Stormphrax lost material and was mated.

game 120, Reckless - Viridithas: The engines slowly exchanged pieces and pawns, evals were stable for a long time. On move 58 the game reached a RBN vs RBN position, both engines had a passer on the queen side. Evals started to increase when Reckless created a passer on the king side. The engines reduced to a B vs N ending, Reckless captured a pawn and pushed one passer to the 7th rank. Viridithas captured this passer but lost its remaining pawns, Reckless trapped the black king and mated.

game 128, PlentyChess - Caissa: Evals increased as the engines exchanged pieces and pawns, the game reached a king and pawns ending on move 51, a 6-man tablebase win for white. PlentyChess was two pawns up with a doubled pawn, both engines pushed passers forward and both queened. PlentyChess gave one pawn and slowly pushed the other, Caissa delayed as much as possible. On move 102 the passer finally promoted, but Caissa placed its king in a corner where a queening would force a draw. PlentyChess chose to promote to a knight, but that was an immediate draw after exchanging queens. Another tablebase implementation bug, this time by PlentyChess. 

Standings after RR2: PlentyChess Integral +5, Caissa +4, Reckless +3, Ceres Stormphrax Viridithas +1, RubiChess 0, Seer -1, Revenge -5, Stoofvlees rofChade -7. Integral had a good RR2 and it now shares first place with PlentyChess. Caissa and Reckless are close behind, and 3 more engines have positive scores at the half. The 4 leaders all have one game pair loss. In this RR PlentyChess gave away a tablebase win against Caissa.

game 135, rofChade - Viridithas: rofChade captured a pawn and exchanged queens. It had two passers, Viridithas gave a bishop to stop one and the engines reduced to a RBN vs RN position. The engines exchanged rooks and an 8-man position remained. rofChade captured a pawn and used its tablebase support to complete the win in 40 more moves.

game 136, Stormphrax - RubiChess: RubiChess gave a knight for two pawns and then pushed a passer but it was not strong enough. The engines exchanged pieces and reduced to a bishop vs pawns ending. The white bishop blocked black passers, Stormphrax queened a passer of its own to win.

game 137, PlentyChess - Ceres: PlentyChess captured a pawn and exposed the black king. The engines exchanged pawns and both created a passer on the queen side, PlentyChess captured a second pawn and its passer was more advanced. PlentyChess pushed the passer to the 7th rank and gave a rook for a knight, then it queened twice and mated.

game 139, Integral - Caissa: There were many exchanges after the start, the game reached a RB vs RB position with white a pawn up. Integral created a passer on the king side, Caissa tried to delay  bu blocking it with its king. Integral captured another pawn, after a while it gave the pawn back and created another passer. This time Caissa lost the bishop, Integral reduced to a tablebase win and converted it in 30 moves.

game 148, PlentyChess - Viridithas: PlentyChess kept its king in the center and doubled queen and rook on the h file. It gave a knight for a pawn to weaken the black pawn support on the king side, in a series of exchanges the engines reduced to a rook ending. PlentyChess was two pawns up with connected passers, Viridithas captured one pawn back but couldn't avoid a queening and mate. 

game 150, Caissa - Ceres: There were many exchanges after the start, the game reached a rook ending with no pawns on the king side and white a pawn up. Caissa created a passer in the center, for a long while the engines mostly shuffled. After 50 moves Caissa started to push the passer slowly, after another 30 moves Ceres lost the rook for the passer and mate followed.

game 165, Reckless - Caissa: Reckless captured an early pawn and created a passer on the queen side. Caissa gave a rook for a knight to capture the passer and the game reached a RRB vs RNN position. In a series of exchanges the engines cleared the king side pawns and reduced to a 6-man R vs N ending. It took Reckless 35 move to complete the win.

game 180, Stormphrax - PlentyChess: The engines opened the c file, they exchanged a few pieces including queens. Stormphrax created a passer in a pawn exchange, the engines shuffled for a while while evals increased. The game reached a RRB vs RRB position, the black bishop moved forward and was trapped and captured. Stormphrax exchanged pieces, then gave back the bishop, queened twice and mated.

game 181, PlentyChess - Integral: The engines slowly exchanged pieces and pawns, evals were mostly stable and slightly increasing. On move 73 PlentyChess captured a pawn, a few moves later the engines reduced to a RB vs RN position. Integral tried to block the white passer, it took PlentyChess 35 moves to push it to the 7th rank. PlentyChess captured a second pawn and then reduced to a winning rook ending. 

game 187, Integral - Reckless: There were no exchanges after the start and evals were stable. On move 45 Reckless gave a pawn and the engines started to exchange pieces and pawns. Reckless tried to expose the white king and attack but was not strong enough. The game reached a QBN vs QR position and Integral had a passer. However, Integral attacked the black king instead, when all the white pieces moved forward Reckless was forced to lose material and was mated.

game 194, Caissa - PlentyChess: The engines exchanged all knights, Caissa captured a pawn and then all major pieces were exchanged. The game reached a same color bishop ending, Caissa shuffled for a long time but after 30 moves it managed to capture more black pawns. Eventually PlentyChess lost the bishop for a passer, Caissa queened another passer to win.

Standings after RR3: Integral +8, PlentyChess +6, Reckless Caissa +5, Stormphrax +4, Ceres +1, Seer RubiChess -1, Viridithas -2, Revenge rofChade -8, Stoofvlees -9. Integral is in the lead with a good RR3 including wins against Reckless and Caissa, and with a loss to PlentyChess. PlentyChess lost twice and drew 3 times as white, it is still in second place but there are 3 engines still close behind. At the bottom of the table there are 3 engines which will surely relegate, and 3 more which are trying to avoid the remaining relegation spot.

game 209, rofChade - Reckless: All pawns were on the board untile move 27, after a few exchanges rofChade captured a pawn. After some shuffling rofChade captured a second pawn and the game reached a QRN vs QRN position. forChade slowly pushed a passer to the 7th rank, in a series of exchanges the engines reduced to a rook ending. Reckless captured the passer but rofChade had two more, it queened and won.

game 216, Ceres - Caissa: The engines exchanged queens early, more pieces were exchanged and the game reached a RB vs RN position. The white pieces were better placed, Ceres moved a rook forward, gave two pawns created an advanced passer. Caissa lost the rook for the passer, all pawns were gone and Ceres converted the tablebase win.

game 220, PlentyChess - Reckless: The engines exchanged pieces and the game reached a BN vs BB position. PlentyChess was a pawn up with a passer on the queen side, it pushed the passer to the 7th rank but the white bishop didn't control the promotion square. The engines shuffled for a long time, eventually Reckless captured the passer but PlentyChess captured the last black pawn. There were two white pawns, it took PlentyChess 25 more moves to start to push them safely. Reckless couldn't stop a queening and mate.

Standings with 5 rounds to go: Integral +10, PlentyChess +9, Reckless +5, Caissa +4, Stormphrax +3, Ceres +1, Seer RubiChess 0, Viridithas -2, rofChade -8, Revenge Stoofvlees -11. Integral continues to lead with PlentyChess close behind. The gap to 3rd place Reckless seems to be sufficient to secure the first two places. PlentyChess also beat Reckless in this RR. At the bottom Viridithas is alone in the 4th relegation spot, but it can still close the small gap to Seer and RubiChess in 5 rounds. 

In round 40 Reckless drew as white against Ceres, Viridithas and RubiChess also drew their game. In round 41 PlentyChess drew as white against Stormphrax and Seer drew as white against rofChade. 

game 247, Integral - PlentyChess: The engines slowly exchanged pieces and pawns, evals were mostly stable. On move 39 PlentyChess gave a pawn, opening a file in the center but giving Integral a passer. After a series of exchanges the engines reduced to a rook ending, PlentyChess captured the passer but Integral was still a pawn up. Integral created another passer, the white king moved forward and PlentyChess lost its rook for the passer, followed by mate.

In round 42 PlentyChess lost to Integral while Reckless beat Viridithas, reducing the gap between then to 1 point with 2 rounds to go. Seer also lost as black, its gap to Viridithas also remained 1 point.

game 253, Reckless - Integral: There were a few minor piece exchanges after the start. After move 30 Integral gave a pawn and opened the center, the white king was exposed and Integral attacked the back rank. Reckless exchanged queens and the game reached a RBN vs RBN position. Reckless created an advanced passer and eventually Integral lost a knight for it. The engines captured all pawns and Reckless won the 7-man position in 45 moves. 

In round 43 Reckless beat Integral and reduced the gap to PlentyChess to 0.5 points. Viridithas beat Stoofvlees and also reduced the gap to Seer to 0.5 points. In round 44 PlentyChess drew as white against Caissa, Reckless drew as black, so PlentyChess finished in 2nd place. Seer lost to Integral and Viridithas drew, their scores were tied in the end. In a special 2-game tiebreak match Viridithas beat Seer, so Seer finished in the 4th relegation spot.