Season 20 league 4

 Final standings

Seer, Weiss and Tucano advance to league 3.  Seer and Weiss led the league from the start. Weiss had a strong first half with 7 wins and a +6 score, then it scored only +0 in the second half with 2 losses. One of these losses was to Seer, which went on to win the league. Tucano and Monolith fought for 3rd place and were very close. Monolith had a tiebreak advantage and needed a win in the last round to qualify, but managed only a draw.

Bagatur finished last and is relegated. It was the weakest engine in the league, losing more than half of its games. All 4 engines from the qualification league survived. It should be noted that relegation is not final until the next season starts, depending on available engines and format changes.

The 3 qualifiers will play in league 3 together with:

Relegated from league 2 in season 19: Nemorino
Played in league 3 in season 19 :  Minic, Pirarucu, Marvin, Topple, Counter
Played in qualification league in season 19: Combusken

Interesting games

Game 1, Monolilth - A0lite: A0lite was a pawn down in a RNN vs RBB ending. It took A0lite a long time to take advantage of its bishop pair, after exchanging rooks it went a pawn up and finally won on move 127.

Game 4, Weiss - Seer: Seer was confident it had an advantage, its eval peaking over (negative) 2.5 after Weiss sacrificed a knight for two pawns. Weiss remained calm and exchanged pieces, the game eventually reached a drawn R vs N ending.

Game 6, A0lite - Bagatur: A0lite failed to convert a knight ending a pawn up with a passer.

Game 12, FabChess - Monolith: The black pieces were stuck behind the pawns. FabChess turned a space advantage to a king side attack, which led to a material advantage. It secured the win with a rook up.

Game 19, Monolith - Weiss: Monolith played better in a RRB vs RBN position, black two pawns up. It reduced to a R vs B ending and used zugzwang to capture a pawn and win.

Game 23, Tucano - Monolith: Monolith was up two pawns in a RBN vs RNN closed position. It took Monolith 40 moves to open the position safely and win.

Game 25, Seer - Halogen: Seer had an eval of 3 in a RBN vs RBN position, it probably missed a win. Halogen had an advanced passer, Seer managed to stop it but settled for a draw.

Game 32, Tucano - FabChess: An advanced passer was enough for Tucano to force a win in a RB vs RN ending. 

Game 40, Weiss - Tucano: Weiss trapped the black queen in a corner, then used a passer to capture a knight. Mate was reached more that 40 moves later.

Scores after 9 rounds: Weiss +6, Seer +4, Tucano +2, Monolith +1, FabChess ChessFighter +0, Halogen -2, A0lite MrBob -3, Bagatur -5. The race at the top of the table is open, Weiss will probably qualify. At the bottom Bagatur is likely to be last.

Game 49, Seer - Weiss: Seer attacked on the king side, and reduced to a winning RR vs RB ending.

Game 58, MrBob - Weiss: MrBob gave a rook for a bishop, it blocked the center with advanced pawns and it had a strong central bishop that dominated the dark squares. Progress was slow, MrBob converted its advantage to material only on move 73, and mated not long afterwards. 

Game 59, Halogen - Tucano:  The game reached a RN vs RB position with Halogen a pawn up on move 17, Halogen played better and managed to convert the win.

Game 66, A0lite - FabChess: A0lite blundered in a winning rook ending, it captured a pawn and ended the game in a drawn 6-man position two pawns up.

Scores after 15 rounds: Seer +7, Weiss +5, Tucano +3, Monolith +2, Halogen +1, ChessFighter -1, FabChess -2, MrBob -3, A0lite -5, Bagatur -7. Seer is leading after Weiss lost twice, both will probably qualify. The 3rd place is still contested. Bagatur is still last with a small probability of survival.

All draws in round 16, no change in table. Seer is sure to qualify.

Game 83, Seer - ChessFighter: ChessFighter shuffled for a long while in a RR vs RBB position, before it found the path to victory. After reducing to a R vs RB ending with white 3 pawns up, possibly with the help of a blunder by Seer, ChessFighter managed to protect and advance its last pawn. Seer lost its rook to stop it, game over.

Monolith needed a win in the last round to reach 3rd place since it had a tiebreak advantage over Tucano. However it only managed a draw playing black against MrBob, Tucano is the 3rd qualifier.