Season 25 league 2

Final standings

Clover, Caissa, Viridithas and DeepSjeng advance to league 1. The 4 qualifiers from the entrance league continue their journey in season 25, all advance for a second time. These engines led the league from the start, together with Arasan. At the half way point Arasan was in 4th place and DeepSjeng trailing by a point. In RR3 Clover, Caissa and Viridithas extended their lead while DeepSjeng and Arasan continued to battle for 4th place. Two rounds to go DeepSjeng and Arasan were tied, but then DeepSjeng beat Arasan in their only decisive game and this was enough to secure the qualification spot.

When the league started Arasan lost a few games in the first rounds against engines that were supposed to be weaker. It turned out that Arasan was run using wrong settings, this was fixed and its first few games were rerun.

The 4 qualifiers will play in league 1 together with:
played in season 24 league 1 - Igel, Revenge, RubiChess, rofChade, ScorpioNN, Seer, Minic, Fritz 

Interesting games

game 1, Viridithas - BlackMarlin: The game reached a RB vs RB position with white a pawn up and each engine with one passer. The engines shuffled for a long time, then BlackMarlin played inaccurately and evals increased. Viridithas captured the black passer, BlackMarlin lost its rook for the white passer, game over. 

game 3, Clover - Halogen: Clover had a pawn majority on the queen side that later became a passer. Clover created a second passer with a piece exchange. In a QRB vs QRN position Clover created a third passer and pushed all three to the 7th rank. Halogen lost two pieces for the passers, and the game ended in a tablebase win. 

game 4, Arasan - Velvet: Velvet had a passive bishop stuck on the king side, the engines opened the queen side and evals increased steadily. Arasan captured a pawn and created a passer in a QBN vs QBN position. Arasan threatened the black king, it gave the knight and captured 3 more pawns. Velvet lost its bishop and couldn't stop all the passers, Arasan queened and mated.

game 5, Caissa - Marvin: The queen side was blocked, Caissa gave a pawn and created a passer in the center. The white king walked to the queen side and Caissa attacked on the king side. The engines exchanged pieces and the game reached a double rook ending with white a pawn up. Caissa had connected passers, Marvin lost material to stop them and was mated.

game 12, Viridithas - Uralochka: Viridithas castled long and opened the king side. Uralochka attacked on the queen side and gave two minors for a rook, in a series of exchanges the engines reduced to a QRN vs QR position with black 4 pawns up. Viridithas captured 3 pawns back and pushed a passer to win. 

game 15, Arasan - Tucano: Arasan gave a knight for 3 pawns and created connected passers. Tucano captured a rook for a bishop and tried to block the passers, Arasan captured another pawn and created another passer. Tucano captured one passer but lost material and eventually was mated.

game 19, BlackMarlin - Marvin: Marvin was up a pawn but its king moved without castling. The game reached a QR vs QR position and the black rook was stuck on the queen side. By the time Marvin freed its rook BlackMarlin captured pawns and reduced to a rook ending with connected passers. Marvin tried to block the passers with its king and was mated.

game 23, Viridithas - Arasan: Arasan was a pawn up but its king moved without castling. Queens were off and Viridithas captured a rook for a bishop, leading to a RRB vs RBN position. After exchanging a pair of rooks the engines captured pawns until there was only one left per engine. Arasan tried to block the white passer but lost its bishop, Viridithas queened and won.

game 25, Clover - BlackMarlin: The king side opened and Clover castled long. BlackMarlin protected its king and the engines exchanged pieces until only QRN vs QRB remained. Clover was a pawn up with a passer, the game ended in a tablebase win.

game 26, Arasan - Uralochka: Uralochka was a pawn up early, the engines gradually exchanged pieces until only RB vs RN remained. Arasan used a pin on the back rank to capture pawns, then queened a passer to win.

game 27, Caissa - Viridithas: Queens were off early, after a while Caissa captured a pawn. The engines shuffled a long time in a closed position, then exchanged pieces until reaching a rook ending. Caissa captured more pawns and queened a passer to win.

game 29, DeepSjeng - Halogen: The engines shuffled in a QRN vs QRN position, then DeepSjeng captured a pawn. Halogen exchanged queens and pushed a passer but DeepSjeng captured it. Halogen lost the bishop to avoid mate, it took DeepSjeng 35 more moves to convert the win.

game 36, Clover - Arasan: Arasan gave a rook and two pawns for a bishop early, putting a knight on d3 and forcing the white king to move. However this did not compensate for the material after Clover moved its king to safety. Clover gave back a rook for a bishop and reduced to a RB vs RN position with 3 pawns up. Arasan couldn't stop the white passers, game over. 

game 38, Caissa - Clover: Clover was up a pawn from the opening. The queen side was blocked and Clover created a passer in the center. There was a lot of shuffling, Clover moved its major pieces to the king side and threatened the black king. Clover moved its king to the center, then used a mate threat to capture all the black pawns on the queen side. It was 5 pawns up, it exchanged pieces and gained more material, the game ended in mate.

game 40, DeepSjeng - Viridithas: Evals started to increase after move 30. DeepSjeng attacked the king side and in a series of exchanges reduced to a RBB vs RB position with black two pawns up. The white bishop pair was strong, Viridithas gave up material and was mated quickly.

game 51, DeepSjeng - Clover: DeepSjeng captured a passer on the queen side, then gave it back to create an advanced passer in the center. Clover gave a rook for a knight to get rid of the passer, the game reached a RBB vs BNN position with black two pawns up. The black pawns were isolated and DeepSjeng captured all of them. Clover tried to stop the last white pawn, it lost material and the game ended in a tablebase win.

Standings after RR1: Clover +5, DeepSjeng +3, Viridithas +2, Caissa Arasan +1, BlackMarlin Halogen Tucano -1, Marvin Uralochka Velvet -2, Wasp -3. There are 5 engines competing for the the 4 qualifying spots. These are the 4 newcomers that advanced from the entrance league, and Arasan that is trying to take one spot from them. The current standings may be biased by the openings, the picture will be clearer after RR2 and the reverse games.

game 70, Velvet - Arasan: The engines opened a few files and exchanged all rooks. The black queen moved forward and was almost trapped, Arasan gave a knight pawns to help the queen escape. In a QBN vs QN position Velvet gave a third pawn and created a passer. After exchanging queens Arasan couldn't prevent a queening, game over.

game 71, Marvin - Caissa: Marvin had an advantage from the opening, there were no exchanges and evals came down. Marvin gave a rook for a knight and pawn to open the king side and attack. Caissa defended its king and evals turned negative. Marvin gave a rook and tried to keep the attack alive, Caissa gave a rook for a bishop while Marvin captured pawns. The game reached a RB vs B with white 3 pawns up, the white passers were not strong enough and Caissa mated.

game 89, Arasan - Viridithas: Viridithas was up a pawn but its king moved without castling. The game reached a RRB vs RRB position, Arasan regained the pawn and created a passer. Arasan then gave a rook for a bishop and pawn and reduced to a B vs R ending. The white passer was fast, Viridithas moved its king to block it while Arasan connected a second passer. Viridithas managed to stop the passers but the king and pawns position left was a win for Arasan.

game 91, BlackMarlin - Clover: BlackMarlin had an advantage from the opening and was a pawn up. After a long shuffle the center opened, BlackMarlin gave a rook and knight to queen a passer. In an unusual imbalance with 3 queens on the board BlackMarlin was not accurate enough, its king and queens were targets for Clover. BlackMarlin tried to push pawns, Clover captured them and went 2 pawns up. The white pieces were pushed back around the king and eventually Clover captured a queen for a rook. Clover captured another piece and then chased the white king and mated.

game 102, Arasan - Clover: Clover was a pawn up but its king moved without castling. Clover managed to develop its king side rook, most pieces moved to the queen side. Arasan had a strong bishop pair, while the two black knights were more passive. Arasan captured two pawns and the game reached a RBB vs RNN position. Arasan slowly pushed a passer forward, Clover lost its rook to stop it. The game ended in a tablebase win.

game 106, Viridithas - DeepSjeng: Viridithas pushed a pawn to f6 and trapped a black bishop in the corner. After some preparation Viridithas gave a pawn and opened the king side, DeepSjeng freed its bishop but the black king was in danger. DeepSjeng traded its queen for a rook and a bishop, reducing to a QR vs RRB position. Viridithas increased the pressure, gained material and won.

game 114, Caissa - Arasan: There were many early exchanges and the game reached a RB vs RB position with white a pawn up. After exchanging bishops it took Caissa 20 moves to capture another pawn. It slowly pushed a passer forward to win.

Standings after RR2: Clover +7, Caissa +6, Viridithas +5, Arasan +4, DeepSjeng +2, BlackMarlin -1, Velvet Uralochka -2, Wasp Tucano -4, Marvin -5, Halogen -6. Caissa had an excellent RR2 with 5 wins, it jumped to 2nd place. The 4 leaders each has one game pair loss, DeepSjeng in 5th has none but it only has one game pair win against the lower ranked engines.

game 146, Clover - Viridithas: The engines mostly shuffled for a long time with all pawns on the board. The first pawn exchange was on move 79, on move 98 the engines opened the center and the game reached a QR vs QN position with black a pawn up. After exchanging queens Clover moved its king forward, it captured most of the black pawns and the game ended in a tablebase win.

game 155, Viridithas - Arasan: The black king was stuck in the center and under attack, Arasan gave a rook for a bishop to stay alive. Arasan tried to counter, it gave a knight for two pawns and attacked but Viridithas moved its king to safety. In a RRN vs RB position Viridithas kept one pawn and captured black ones gradually, the game ended in a tablebase win.

game 168, Clover - Arasan: Clover was a minor piece up but its queen side pieces were not developed. Arasan played inaccurately, it gave pawns and tried to attack through the center but Clover kept its king safe and developed its pieces. The engines exchanged pieces until only RBN vs RB remained, Arasan gave up material and was mated.

game 194, DeepSjeng - Caissa: Caissa had an eval advantage from the opening, material was equal and the engines gradually exchanged pieces, the game reached a double knight ending with black a pawn up. After sone shuffling the engines exchanged a pair of knights, then DeepSjeng allowed the remaining knights to be exchanged and regained the pawn. This was a bad idea since Caissa had a passer, the white king could not defend both sides of the board and the game ended in a tablebase win.

Standings after RR3: Clover +11, Caissa Viridithas +10, DeepSjeng +5, Arasan +3, BlackMarlin 0, Uralochka Velvet -3, Wasp -5, Marvin -7, Tucano -9, Halogen -12. The 3 leaders are going to qualify, the final order is not decided yet. The 4th qualification spot is still a race between DeepSjeng and Arasan. DeepSjeng had a good RR3 with 4 wins against lower ranked engines, Arasan had only 1 and it has to be better in RR4 to have a chance.

game 199, BlackMarlin - Viridithas: Evals increased from the start in a closed position with equal material. BlackMarlin opened the queen side and threatened the black king, then moved a rook forward on the king side. After some shuffling Viridithas exchanged queens to get its king to the center, the game reached a BN vs BN position with white two pawns up. Viridithas lost a bishop but couldn't stop a white passer, BlackMarlin queened and mated.

game 201, Halogen - Clover: Halogen started with an eval advantage but Clover managed to equalize. Halogen was not careful, itlet Clover open the queen side and reduce to a RRN vs RRB position. Material was equal but Clover had connected passers it pushed forward and Halogen couldn't stop. Clover gave some material and queened one passer, then slowly converted the QB vs RR ending. 

game 221, Arasan - Viridithas: Arasan had an eval advantage and more space, the engines exchanged most minor pieces. Arasan opened a file on the king side and gave a pawn while it threatened the black king. In a QRR vs QRR position Arasan moved its queen to the center and the black king had to leave the corner. After exchanging a pair of rooks Arasan moved its rook to the 7th rank, Viridithas gave its queen to get rid of it. Arasan queened a passer to win.

game 234, Arasan - Clover: Arasan had an eval advantage from the start, the engines gradually exchanged pieces and the game reached a RN vs RN position. Arasan restricted the black king to the h file, it gave a pawn and moved its king forward through the center. Clover couldn't protect its pawns, Arasan captured all of them and was left with two white pawns. The endgame was slow, Arasan gave one pawn away but the 7-man position was still a win. 

Standings with 5 rounds to go: Caissa +13, Clover +12, Viridithas +8, DeepSjeng +6, Arasan +5, BlackMarlin +1, Uralochka Velvet -4, Wasp -6, Marvin -7, Tucano -11, Halogen -13. Clover and Caissa are battling for 1st place, Viridithas lost twice and will probably finish 3rd. Arasan still has hope, it won twice against the leaders and reduced the gap to DeepSjeng to 0.5 points. The DeepSjeng-Arasan game 257 may determine the 4th place.

game 236, Clover - Caissa: There were almost no exchanges after the start, by move 35 only one pair of pawns and one pair of bishops were exchanged. Clover gave a pawn and opened the king side, Caissa surrounded its king with minor pieces for protection. Caissa gave a rook for a bishop and pawn, there was a period of shuffling and then Clover managed to move a rook  to the 7th rank. Clover captured a bishop and Caissa's defense collapsed. Clover gained more material and mated.

Standings with 2 rounds to go: Clover +14, Caissa +12, Viridithas +9, DeepSjeng Arasan +6, BlackMarlin +2, Uralochka -3, Velvet -6, Marvin -8, Wasp -9, Tucano -10, Halogen -13. Clover is back in the lead after it beat Caissa. Arasan managed to close the gap to DeepSjeng in 4th after DeepSjeng held a draw against Clover and Viridithas, while Arasan only managed a draw against Caissa playing black with an eval advantage. 

game 257, DeepSjeng - Arasan: Arasan blocked its own knight and lost it for a pawn early in the game. There was no compensation for the lost piece, the engines gradually exchanged pieces until only RN vs R remained. DeepSjeng was patient, it went a pawn up and created a passer, the game ended in a tablebase win.

DeepSjeng secures the 4th promotion spot with this win, it is a point ahead and has a tiebreak advantage over Arasan before the last round.