Season 24 league 1

Final standings

Koivisto and Berserk advance to the premier division. Koivisto led from the start, its lead increased and none of the other engines came close. It beat all engines in at least one game pair, except for drawing against Berserk and losing one game pair to Seer. The race for 2nd place was very close with 5 engines within a point of each other until the last rounds. Berserk qualified in the end, it is the only engine without any game pair loss in the league, and it had two game pair wins against the other engines in the race.

Minic, Fritz, BlackMarlin and Marvin are relegated to league 2. These engines were at the bottom of the table from the start and their relegation was predictable. They lost 48/64 of the game pairs played against the higher ranked engines, BlackMarlin was the only one that managed one game pair win against ScorpioNN. Except for Minic the relegated engines advanced from league 2, Igel is the only qualifier that survived league 1.

The two qualifiers will play in the premier division together with:
Stockfish Leela KomodoDragon Ethereal Stoofvlees SlowChess - all played in season 23 premier division.

Interesting games

game 8, Revenge - RubiChess: Revenge castled long while RubiChess did not find the right time to castle. Revenge gave a pawn and opened the center, then it attacked the black king and forced it to move to the king side. The result of the attack was a QRB vs QRB position with white two pawns up. Revenge captured the remaining black pawns, RubiChess couldn't avoid a queening and game over.

game 13, Koivisto - Igel: The engines the d file and Koivisto placed a rook safely on d6, then gave a bishop for a pawn and exposed the black king. A knight sacrifice opened the 6th rank and Koivisto chased the black king with its queen and rook all the way across the board. The chase stopped when Koivisto captured a queen for a rook, resulting in a Q vs RNN imbalance with white 3 pawns up. There were 3 connected white passers on the king side, Igel tried to block but after exchanging a pair of rooks Koivisto's passers were unstoppable. The game ended in mate with 3 queens on the board.

game 15, ScorpioNN - rofChade: ScorpioNN had a bishop pair advantage, pawn exchanges opened the board and the game reached a RBB vs RNN position with white a pawn up. Koivisto created a passer on the king side, then captured another pawn and created a passer on the queen side. rofChade blocked the passers until ScorpioNN exchanged bishop for knight and the white king moved forward to help. ScorpioNN pushed both passers slowly, eventually queening both and mating.

game 18, BlackMarlin - Revenge: The engines shuffled in an opposite color bishops ending with white a pawn up. This should have been a draw but Revenge blundered and BlackMarlin managed to avoid a 50-move draw and capture two pawns, enough for a win.

game 19, Igel - Revenge: Igel had a space advantage and a significant eval advantage from the start. Exchanges opened the position, Igel went two pawns up with two passers on the queen side. One passer reached the 7th rank, Revenge lost a rook to capture it and Igel converted the RRN vs RB position easily. 

game 24, Koivisto - Berserk: The game reached a RBB vs RNN position and evals slowly increased. Koivisto went a pawn up and created two passers, one on each side. Berserk had a passer in the center but it was busy trying to stop the white passers advance. Berserk lost a knight for one passer, the game ended in a tablebase win with one last white pawn.

game 28, RubiChess - rofChade: Evals slowly increased after move 20, both engines created a passer but the white passer was more advanced and better protected. The game reached a RRN vs RRB position, RubiChess captured the black passer and pushed its own to the 6th rank, then captured two more pawns. After all rooks were exchanged the game ended in a tablebase win.

game 36, Berserk - ScorpioNN: Berserk was up a rook for a knight for a short while but gave the material back, resulting in a QRB vs QRB position. The black king was more exposed and the black pawns isolated, Berserk captured a pawn and then captured a rook for a bishop. Berserk's evals showed mate scores, it exchanged queens and reduced to a tablebase win.

game 37, ScorpioNN - Igel: ScorpioNN was 2 pawns up in a BN vs BB position with high evals, but it couldn't find a way to convert. 

game 49, Fritz - Igel: The white king was uncastled in the center, but more significantly Fritz had a pawn on h6 and there was a black bishop trapped in the corner. Igel had the strength to capture the h6 pawn but it left it there, probably not wanting an attack on the h file. Fritz captured a pawn on the queen side, Igel moved its bishop out of the corner and later traded it for a white bishop. Fritz created a passer on the queen side, after exchanging queens Igel lost a rook to capture the passer. The game ended in a tablebase win.

game 55, Igel - rofChade: Evals were high and increasing from the start, the g file was half opened and the black king was under threat. rofChade exchanged pieces to protect its king, Igel captured pawns, the game reached a RB vs RN position with white a pawn up. For a while rofChade tried to force stalemate, Igel avoided that and reduced to a tablebase win.

game 58, Berserk - Revenge: Evals started to increase around move 30, Revenge controlled the open a file and Berserk pushed the h pawn forward. Berserk opened the h file and increased the pressure on the king side, then it gave a bishop for a pawn and exposed the black king. In the attack Berserk sacrificed a rook but captured the queen, leading to a QN vs RBB position. Revenge tried to protect its exposed king with its pieces, Berserk used a passer to capture a bishop, then reduced to a won knight vs pawns ending. 

game 63, Revenge - ScorpioNN: For over 30 moves evals were below 1, ScorpioNN was a pawn up and no worried. Evals started to jump when in a series of exchanges Revenge gave a piece and reduced to a RN vs RBN position. Revenge created connected passers as well as captured two advanced black pawns. One passer was on the 7th rank and ScorpioNN had to give the rook to stop it. The game ended in a tablebase win. 

game 64, Seer - Berserk: Seer focused its pieces on the king side with a pawn on h6, while Berserk went a pawn up and its queen moved forward on the queen side. Seer was strong on the dark squares and it threatened mate on the long diagonal, a series of exchanges reduced to a Q vs RB ending. Seer captured pawns and the h6 pawn became a passer, Berserk tried to trap the queen but Seer used zugzwang to force a queening and win.

Standings after RR1: Koivisto +4, Igel RubiChess +2, Berserk ScorpioNN +1, Revenge Seer rofChade 0, Minic -1, Fritz -2, Marvin -3, BlackMarlin -4. Koivisto has a small lead, there a 7 engines within one point of second place. The 4 engines with negative scores include 3 of the qualifiers from league 2.

game 85, Revenge - Igel: A long series of exchanges reduced to a same color bishop ending with white a pawn up. All pawns except one were blocked, Igel tried to make sure the white king couldn't move behind the pawns. After a long shuffle Revenge found a way to force the black bishop away and the white king advanced. The black king moved to protect the pawns in the center, Revenge gave two pawns and queened on the king side, game over. 

game 90, Berserk - Koivisto: The engines gradually exchanged pieces while evals increased, the game reached a double rook ending with white a pawn up. Koivisto regained the pawn but Berserk created connected passers. Koivisto blocked the passers and avoided exchanging rooks, Berserk captured two pawns and pushed a passer to the 7th rank. Koivisto pushed its last pawn forward, it captured a white passer and exchanged a pair of rooks. Both engines queened a pawn, Koivisto was first but Berserk promoted with check, this was enough to force mate.

game 91, Igel - Berserk: Igel had an eval advantage despite sacrificing a knight, it threatened the black king through the open king side. Berserk found a way to walk its king safely to the center and evals came down. After a period of shuffling evals turned negative as the engines opened the position. Berserk captured pawns and created passers, the game reached a queen ending with white 3 pawns up which Berserk converted easily. 

game 92, Koivisto - ScorpioNN: The game reached a QRR vs QRR position with white a pawn up. The black king was exposed, Koivisto gave checks and captured two more pawns, then reduced to a winning queen ending. 

game 94, rofChade - RubiChess: There were a few pawn and minor piece exchanges in the first 50 moves and evals were mostly stable. After a period of shuffling there was a series of exchanges that left a QN vs QB position with white a pawn up. The engines cleared the queen side pawns and shuffled some more. rofChade's eval started to increase, it found a way to exchange queens and move its king forward. The black bishop and the white pawns were on opposite color squares, rofChade managed to capture a pawn and push a passer to the 7th rank, enough to win. Did RubiChess blunder here?

game 102, ScorpioNN - Berserk: The game reached a BB vs BN with white a pawn up, ScorpioNN had advanced connected passers and Berserk also had a passer. There was a long period of mostly shuffling, on move 100 Berserk exchanged its knight for one of the white bishops and reduced to an opposite color bishop ending. However, ScorpioNN created another passer and Berserk couldn't control them all, it lost the bishop for a passer, game over. Could Berserk have held here?

game 105, Koivisto - RubiChess: There were many early exchanges and the game reached a RRB vs RRB position with white a pawn up. Pawn exchanges opened files and Koivisto captured another pawn. RubiChess regained a pawn and exchanges bishops, evals started to increase after move 70. At first the engines seemed to shuffle but Koivisto found a way to exchange a pair of rooks and capture a pawn. Koivisto used passers to win.

game 110, Seer - rofChade: After the engines exchanged queens rofChade moved a rook forward on the queen side and Seer blocked its way back. rofChade didn't try to free its rook, Seer moved its king to take it and rofChade traded the rook for a bishop. Seer reduced to a R vs B ending, it captured pawns and queened a passer to win.

game 114, Fritz - ScorpioNN: ScorpioNN was up a pawn with the black queen moving forward on the queen side, for a long time it seemed Fritz tried to hunt the black queen and ScorpioNN refused to move it back again. After move 45 evals started to increase, the black queen moved to the king side and threatened the white king. Fritz counter-attacked from the queen side, it regained the pawn and created a passer. ScorpioNN could not prevent a queening and Fritz mated.

game 118, Koivisto - Revenge: Revenge gave a pawn, Koivisto thought this was a mistake and it led to a B vs R trade. For a while there were no exchanges though evals slowly increased. A series of exchanges reduced to a R vs BN position, Koivisto captured a pawn and created connected passers on the queen side. Koivisto gave a rook for a bishop to make the passers unstoppable, mate was quick after the queening.

game 124, Revenge - Berserk: Thee were many early exchanges that left only QBN vs QBN, evals started to increase while the remaining minor pieces were exchanged. Revenge was a pawn up in a queen ending, it had a passer and its king was less vulnerable. Progress was slow but sure, Revenge captured another pawn and pushed its passer forward to force the win.

game 127, Igel - RubiChess: The engines exchanged pieces and material was equal but evals slowly increased. The black pawn structure was weak, when only RN vs RB remained Igel captured two pawns. Both engines had advanced passers, but after both were gone RubiChess had no more resources. Igel pushed its two remaining pawns to win. 

game 130, Berserk - Seer: The game reached a RRN vs RRN position, material was equal but Berserk had a space advantage and evals were increasing. Berserk created connected passers in the center with pawn exchanges, and exchanged a pair of rooks. Seer had passers on the king side but it could not stop the white pawns charging in the center and lost its knight. Berserk queened another passer and mated.

Standings after RR2: Koivisto +8, Revenge +4, Igel Berserk +3, ScorpioNN RubiChess +2, rofChade +1, Seer 0, Minic Fritz -4, BlackMarlin -7, Marvin -8. Koivisto is leading with 8 game pair wins and no loss. The fight for 2nd place is wide open with 5 engines within a point of each other. Revenge came back to current 2nd with 5 wins in RR2 (and one loss to Koivisto), drawing 3 game pairs that it lost  in RR1 (including against BlackMarlin). The bottom 4 engines are clear at this point, 3 qualifiers and Minic. They lost 23/32 game pairs against the other 8 engines with no win.

game 134, Koivisto - rofChade: rofChade moved its king side rook early, the black king moved forward without castling. Koivisto went up a pawn and had an advanced passer on the queen side, rofChade hid its king behind the passer. The engines exchanged pieces and pawns, rofChade captured the passer and Koivisto captured a second pawn. In a RRB vs RRN position Koivisto captured a third pawn, it queened a passer and mated.

game 136, ScorpioNN - Seer: Queens were off early, the engines exchanged pieces and pawns gradually and there were long periods of shuffling with mostly stable evals. On move 75 ScorpioNN went a pawn up in a RRB vs RRB position and evals started to increase. ScorpioNN captured a second pawn and exchanged a pair of rooks. After ScorpioNN captured a third pawn Seer could not stop the white passers, game over.

game 142, Minic - ScorpioNN: ScorpioNN was up a pawn early, but Minic had an eval advantage. After a series of exchanges the game reached a RR vs RB position. ScorpioNN pushed pawns forward on the queen side, Minic exchanged a pair of rooks and pushed a passer on the king side. The game ended in a tablebase win just before Minic captured the bishop the passer.

game 143, rofChade - Berserk: rofChade went a pawn up and the game reached a RB vs RN position. rofChade had a pawn majority on the queen side, the white king moved to assist the pawns while the white rook moved forward. After some preparations rofChade created a passer and captured another pawn, then exchanged rooks. The white king came forward and rofChade trapped the knight, Berserk couldn't avoid a queening and mate.

game 145, Koivisto - Igel: Koivisto gave 3 pawns and a rook, Igel's king was exposed in the center and the black queen far on the 1st rank. Koivisto attacked the black king, Igel surrounded its king with pieces. Igel gave back the material but in a QRN vs QRN position its king was still in danger. Koivisto captured a knight and exchanged queens, it took more than 30 moves to capture 2 pawns and force mate.

game 149, RubiChess - Seer: The engines castled in opposite directions, RubiChess gave a pawn and half opened the h file facing the black king. Seer tried to counter on the queen side but was not effective. RubiChess attacked the black king, it won a bishop and Seer hid its king behind a white pawn. In a QRB vs QR position RubiChess captured all the black pawns, mate followed.

game 151, Igel - Revenge: The engines gradually exchanged pieces and the game reached a RRN vs RRN position. Both engines had a passer on the queen side. Revenge captured the white passer, Igel captured two pawns and created a passer in the center. Igel captured the black passer, Revenge tried to avoid exchanging pieces but eventually it lost a knight for a passer and the engines exchanged a pair of rooks. Igel reduced to a tablebase win.

game 162, Revenge - Seer: There were only a few pawn exchanges until move 49, though evals slowly increased. Then in a series of exchanges the queen side opened and all rooks were off. Revenge created connected passers and reduced to a BNN vs BBN position. Eventually Seer lost a piece for a passer, the game reached a B vs pawns ending that Revenge converted easily. 

game 173, Revenge - rofChade: Both engines did not castle, evals slowly increased as the engines exchanged pieces and pawns. The game reached a RBN vs RBN position, with 3 white pawns on the queen side and 3 black pawns on the king side. The white passers were more dangerous and supported by the king, rofChade chose to give a bishop to capture two pawns. Revenge protected its last pawn while capturing all the remaining black pawns, then converted the 8-man position to a tablebase win.

game 179, Berserk - RubiChess: The engines castled in opposite directions, the black king was more exposed after Berserk opened the f file and exchanged a pair of rooks. Berserk was patient and there was a period of shuffling with evals increasing slowly. RubiChess exchanged a pair of pawns and opened the center, Berserk exposed the black king and threatened mate on the long diagonal. RubiChess traded bishops and removed the threat, in a QRN vs QRN position Berserk used the exposed black king to exchange queens and capture 3 pawns. RubiChess couldn't stop the passers, game over.

game 182, RubiChess - ScorpioNN: ScorpioNN kept its king in the center, RubiChess opened the d file and exchanged queens. RubiChess sacrificed a bishop to expose the black king, then regained the material and placed a rook on the 7th rank. In a double rook ending RubiChess managed to move its second rook to the 7th rank, the black king was trapped and waited to be mated by a promoted passer. 

game 190, Berserk - Revenge: Berserk went up a pawn early, it had a pawn majority on the queen side. The engines exchanges pieces and pawns with evals slowly increasing. Eventually Berserk created a doubled passer, Revenge stopped one passer on the 7th rank but lost a bishop. The white king came forward, Berserk gave a rook for a knight and reduced to a tablebase win in a BN vs R ending. 

game 195, Revenge - ScorpioNN: The game reached an opposite color bishops ending with white two pawns up. After a long shuffle Revenge gave a pawn and created a passer, then ScorpioNN blundered and Revenge's eval indicated a win. ScorpioNN saw the mistake only 7 moves later. With only 2 white pawns and one black left, the white bishop protected a passer on the 7th rank and controlled the black pawn. Revenge had time to walk with its king to assist the other white pawn, forcing ScorpioNN to lose its bishop and the game.

Standings after RR3: Koivisto +12, Igel Berserk Revenge +5, RubiChess +4, rofChade +3, ScorpioNN +1, Seer 0, Minic -7, Fritz -8, Marvin BlackMarlin -10. Koivisto is on its way to win the league. There are 3 engines tied in 2nd place and two more within a point. 

game 206, RubiChess - Revenge: Revenge captured a pawn early but was slow in developing the queen side pieces, RubiChess opened the h file and threatened the black king. RubiChess gave another pawn and added a threat on the long diagonal, Revenge blocked with a pawn but lost a bishop. RubiChess pushed pawns and opened the f file, it also created an advanced passer in the center. Revenge tried a desperate attack on the white king, this only delayed mate.

game 209, Berserk - rofChade: The center and king side were mostly blocked and the attention of both engines was on the queen side. The engines opened the queen side and cleared away all pawns, Berserk placed a protected knight on c5 and threatened to move a rook forward. rofChade gave a rook to capture the white knight, the game reached a QR vs QN position. Berserk used threats on the black king to force a queen exchange, the white king moved forward. Berserk created an unstoppable passer to win.

game 213, rofChade - ScorpioNN: The engines gradually exchanged pieces and pawns, rofChade went a pawn up with a passer on the queen side. The game reached a RN vs RB position, the engines mostly shuffled for 30 moves and evals started to increase. rofChade managed to get its king forward and to block the black king away from the passer. rofChade gave a rook for a bishop and ScorpioNN could only stop the passer by giving its rook. The knight vs pawns ending was a win for white.

game 226, rofChade - RubiChess: rofChade was up a pawn early, the engines exchanged pieces until only QB vs QB remained. Evals slowly increased, RubiChess was weak on the dark squares and its queen had to protect the king since the black bishop was light squared. rofChade opened the king side and moved its king forward. After exchanging queens rofChade gave a pawn and created a passer, RubiChess lost its bishop to stop the passer. The bishop vs pawns ending was a win for white.

Standings with 6 rounds to go: Koivisto +13, Igel Berserk +6, RubiChess Revenge +5, rofChade +4, ScorpioNN +2, Seer 0, Minic -7, Fritz -10, BlackMarlin -11, Marvin -13. Every game counts in the race for 2nd place, especially head to head decisive results. Berserk beat rofChade and is in 2nd place tied with Igel. RubiChess beat Revenge but lost to rofChade, Revenge also failed to beat BlackMarlin. rofChade also beat ScorpioNN, it is still hanging on the leaders, but time is running out.

game 229, Seer - Igel: Seer was a pawn up early, the white king moved forward without castling. Seer created a passer on the queen side, Igel regained the pawn but evals slowly increased. Seer gave a rook for a knight and pawn to add a connected passer and Igel tried to block. Seer pushed one passer to the 7th rank, after a while the game reached a QN vs QR position. The white king came forward, Igel traded all pieces to stop the passer. The material was equal but Seer had an unstoppable passer to win.

game 231, BlackMarlin - rofChade: BlackMarlin gave a pawn and opened the king side, its king stayed in the center and later it castled long. The engines exchanged pieces and BlackMarlin captured pawns, the game reached a RBN vs RBB position with white two pawns up. BlackMarlin had a passer still on the 2nd rank, the engines exchanged knight for bishop, it took 35 moves before the passer moved. The white king moved forward to support, BlackMarlin captured a pawn and created more passers. rofChade couldn't prevent a queening and mate.

game 235, Igel - ScorpioNN: Igel attacked the king side early, resulting in a R vs NN imbalance and the black king walking to the queen side. Pawn exchanges opened the board, Igel targeted the exposed black king and captured pawns. It was 4 pawns up when ScorpioNN captured a rook for a bishop and reduced to a QR vs QRN position. ScorpioNN captured a few pawns back but Igel reduced to a winning queen ending. 

game 237, Koivisto - RubiChess: Evals increased slowly as the engines exchanged pieces and pawns. The game reached a RN vs RN position with white a pawn up. Koivisto had a queen side passer, once the white king came to assist RubiChess could not stop the passer advancing. Koivisto queened the passer and mated.

game 239, rofChade - Revenge: The engines castled in opposite directions, both pushed pawns facing the opponent's king. Revenge opened the a file, then gave a knight for two pawns on the king side. Revenge tried to attack the white king, it gave a rook for a knight but rofChade gave the exchange back to keep its king safe. rofChade pushed a passer to the 7th rank and reduced to a RN vs R position. The game ended in a tablebase win.

game 245, RubiChess - Berserk: The engines castled in opposite directions, there were no pawn attacks and the engines gradually exchanged pieces. Evals slowly increased though Berserk went a pawn up, the game reached a RB vs RN position. RubiChess regained the pawn and created connected passers on the queen side. The black king moved to block the passers, Berserk tried to counter with a passer in the center but was not strong enough. RubiChess had a rook on the 7th rank, the black rook had to defend the back rank, eventually RubiChess captured the knight and won. 

Standings with 3 rounds to go: Koivisto +14, Berserk Igel Revenge RubiChess +6, rofChade +4, ScorpioNN Seer +1, Minic -8, Fritz BlackMarlin -11, Marvin -14. Four engines tied for 2nd place! Igel and rofChade lost games as black against weaker engines, top engines beat weaker engines as white. rofChade probably does not have a chance of  being 2nd at this stage, for the others every game counts.

game 248, ScorpioNN - RubiChess: ScorpioNN castled long and opened the king side, RubiChess kept its king in the center. RubiChess gave a rook for two knights, ScorpioNN attacked through the open e file and the black king had to run to the king side. The engines reduced to a RB vs BN position, ScorpioNN had passers on both sides. RubiChess lost the bishop to stop one passer, the other queened and ScorpioNN mated.

Standings at the top with 2 rounds to go: Koivisto +14, Berserk Igel +7, Revenge +6, RubiChess +5, rofChade +4. Igel and Berserk beat weaker engines as white, rofChade only managed a draw, Revenge held a draw as black against Koivisto. rofChade and RubiChess are probably out of the race.

game 253, rofChade - Igel: There were only a few exchanges after the start, most of the board was blocked by long pawn lines. A pawn exchange opened the h file, then rofChade used a knight exchange to create a passer in the center. rofChade gave the passer and created another on the king side, the game reached a QBN vs QBN position with white a pawn up. Igel tried to attack with its queen, rofChade captured more black pawns and was 4 pawns up. After exchanging queens nothing could stop the passers, game over. 

game 255, Seer - Koivisto: Seer was up a pawn from the start, the engines exchanged pieces until only QRR vs QRR were left. Evals started to increase, the engines exchanged all rooks and Seer created a passer. Koivisto captured white pawns while Seer pushed he passer to the 7th rank. The game reached a 7-man position won for white, Seer had access to 7-man tablebases but it still took almost 50 moves to get to a 6-man adjudication. 

Standings at the top before the last round: Koivisto +13, Berserk +7, Igel Revenge RubiChess +6, rofChade +5. Berserk held a draw as black against Revenge, after Igel's loss Berserk is alone in 2nd place. RubiChess beat a weaker engine as white, still has a small chance. 

Igel and RubiChess drew their last game. Revenge held a draw as black against ScorpioNN. Berserk only needed a draw but it won as white against Seer, making sure it qualifies to the premier division.