I have been following the qualification league results without looking at too many games. Round 22 of 34 is being played now, more than half the league is over. I have some time now to go over the archive, look for interesting games and make some observations in hindsight. If I overlook important events feel free to comment on them below.
NN engines
There are two NN engines in the lead. ScorpioNN improved a lot, it was very weak in season 14, while in season 15 it had a stability problem. This season ScorpioNN is without loss so far and will very likely qualify for league 2. Stoofvlees is a new engine in TCEC which was supposed to be strong, and indeed it too is on its way up. Stoofvlees' eval scaling is not the same as the other engines, its eval rarely (or never) goes over 10. As a result the TCEC win rule never applies in its decisive games and they are played until mate or 6-man TB adjudication.
There is a 3rd NN engines in the league, ChessFighterNN. Unlike the two leaders ChessFighterNN's score is -10 and it is close to the bottom of the table. Using a neural net is not enough to become a strong engine.
Jumbo and Bagatur are losing
The two engines at the bottom of the table, Jumbo and Bagatur, have 31 losses between them out of 40 games. Both played in season 15 and both have updated versions, but the other engines in the league are still much stronger. Jumbo has lost 18/20 games, Bagatur has wins against ChessFighterNN and Asymptote, but the win against Asymptote was due to a bug that caused Asymptote to lose on time in a winning position with mate in sight. There are several games where these engines blunder in a drawn position in the middlegame or endgame.
CPU Leela
LCZeroCPU is a version of Leela that runs on CPU only, it has a small net to improve its performance. It is much weaker than the full GPU version that was the season 15 champion, but it is in 3rd place and could have qualified in this league. However, it is not in the formal race and its games are just for entertainment. These games will be ignored and will not affect the other engines' scores. This may cause some confusion when trying to understand the current qualification race standings.
Top 6 engines
The top 6 engines qualify to league 2. After 20 rounds the scores were (ignoring LCZeroCPU games): ScorpioNN +14, Stoofvlees +13, Wasp +9, Marvin +6, Topple +4, Winter +3, Asymptote +2, chess22k +1, The Baron 0, Rodent 0. The race for places 5-6 is quite open. Keep in mind that Asymptote lost a full point when it crashed against Bagatur, with this point it would be in 5th place.
Notable games
Game 15, Topple - ChessFighterNN: ChessFighterNN gave a rook for a knight and developed a strong king side attack. Topple had to give material to stop the advancing black pawns, losing the game.
Game 42, LCZeroCPU - Topple: LCZeroCPU was 4 pawns up in a RB vs RB position, the game was nearly adjudicated with the win rule, Topple already seeing mate. Then LCZeroCPU fell into a stalemate trap, the black king couldn't move and the black rook chased the white king. A capture would have ended the game immediately, Leela kept playing until reaching the 50-move draw.
Game 53, Bagatur - ChessFighterNN: Bagatur's only win came after ChessFighterNN chose to reduce to a BBN vs RB position. Bagatur's pieces were stronger, it forced ChessFighterNN to give its rook for a bishop and the extra piece was enough to win.
Game 61, Minic - Topple: Topple blundered in a closed position, Minic created a passer and Topple's position crumbled (toppled over?).
Game 68, Wasp - Marvin: Wasp had an eval advantage of over 1 that came down to 0 in a QRB vs QRN position. Evals became negative after Wasp gave a rook for a knight and two pawns. Marvin was better in the endgame, reducing to a winning B vs R position.
Game 73, ChessFighterNN - Winter: ChessFighterNN gave a bishop and thought its attack on the exposed black king was enough compensation. Winter exchanged pieces and had a winning position, but it allowed ChessFighterNN to force a perpetual check draw.
Game 74, Igel - chess22k: The engines avoided a 50-move draw and opened the position, Igel won a pawn and the game reduced to an opposite color bishop ending. chess22k blundered and allowed Igel to capture a second pawn, two advanced passers were enough for a win.
Game 100, Winter - Topple: Winter was two pawns up in a QB vs QB position. After Winter exchanged queens the remaining bishops were of opposite colors, keading to a draw.
Game 122, Cheese - ScorpioNN: ScorpioNN had an eval advantage in a QB vs QB position, it allowed Cheese to sacrifice the bishop and get a perpetual check draw.
Game 134, Topple - Asymptote: Asymptote gave a rook for a bishop and a pawn, it had a strong bishop pair and a passer in a QRN vs QBB position. Topple couldn't stop the passer and its attack on the black king was not strong enough, Asymptote captured the knight and won the game.
Game 169, chess22k - Tucano: chess22k was up a rook for 3 pawns in a QRR vs QR position but failed to convert. Tucano managed to push a pawn to the 2nd rank and forced a perpetual check draw.
Game 172, Winter - Bagatur: Winter was a pawn up in an opposite color bishop ending. Stockfish saw a way to force a win but Winter didn't and Bagatur managed to hold.
Game 178. Stoofvlees - LCZeroCPU: Evals started around 0 and increased very slowly. Stoofvlees created a passer on the queen side, then captured a pawn and reduced to a QRB vs QRB position on move 50. LCZeroCPU countered with a passer on the king side, Stoofvlees exchanged queens and captured the passer on the 2nd rank. LCZeroCPU had to give its bishop to stop the white queen side passer, then it gave up the rook in despair and lost. First loss for LCZeroCPU.
No comments:
Post a Comment