Sable 2.0.0 - new version chess engine

Sable, a UCI chess engine written from scratch in C++, with a self-trained NNUE evaluation. Estimated strength: ~3200 CCRL (single-threaded, estimated) — see Strength.
Sable was built and trained on a single desktop PC (Intel i7-11700K + RTX 3070) — the neural network's training data was generated entirely by the engine playing itself, with no external datasets or pretrained weights.

Author: dylan2554

Sable 2.0 what's new?

we're getting serious now...

Ok SO! I trained a decent net, 'Vex' has a (768x16hm->256)x2->1 arch, and is trained on 3 iterations of 800 million positions labeled by the previous iteration 🔥

Lots of search improvements thanks so much to members of the Stockfish discord and MattBench discord for patch ideas and help etc.

Lots of speed improvements from analyzing flame graphs and other such nerdy stuff.

Removed any dependancy on cozy chess :p

Performance

Sable 2.0 performance against 1.1:

STC

Elo   | 556.98 +- 34.57 (95%)

Conf  | 8.0+0.08s Threads=1 Hash=16MB

Games | N: 2042 W: 1907 L: 24 D: 111

Penta | [1, 0, 27, 101, 892]

https://chess.n9x.co/test/7272/

LTC

Elo   | 602.35 +- 80.56 (95%)

Conf  | 40.0+0.40s Threads=1 Hash=16MB

Games | N: 628 W: 597 L: 7 D: 24

Penta | [0, 0, 8, 22, 284]

https://chess.n9x.co/test/7273/

VLTC

Elo   | 632.26 +- 180.32 (95%)

Conf  | 120.0+1.20s Threads=1 Hash=16MB

Games | N: 254 W: 243 L: 2 D: 9

Penta | [0, 0, 3, 7, 117]

https://chess.n9x.co/test/7274/

Sable 2.0 performance against Stash 35

STC

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Results of Sable-2.0.0 vs Stash-35.0 (8+0.08, 1t, 16MB, UHO_Lichess_4852_v1.epd):

Elo: -68.35 +/- 16.71, nElo: -90.25 +/- 21.49

LOS: 0.00 %, DrawRatio: 39.44 %, PairsRatio: 0.36

Games: 1004, Wins: 273, Losses: 468, Draws: 263, Points: 404.5 (40.29 %)

Ptnml(0-2): [82, 141, 198, 52, 29], WL/DD Ratio: 4.66

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The above benchmarks leads me to believe Sable is around 3300 in LTC.

Sable 2.0.0 download