Chessnix 1.4 - new version chess engine

Chessnix - UCI chess engine

Author: Ericlangedijk  github:https://github.com/ericlangedijk/chessnix

We've begun our first tests of this engine. The author estimates its playing strength at around 3000 ELO, but we believe this is 200-300 points too high.

Chessnix 1.4 what's new?

• Compiler: Zig 0.15.2.
• Stronger: Optimistic estimation: ~3300 ELO (blitz ~3350).
• Added: Evaluation: knight outpost refinement, bishop on long diagonal.
• Added: Endgame scaling to guide the search.
• Added: KBN_K mating logic.
• Changed: Correction History (better math, small individual signals, 5 tables for 5 position hashkeys).
• Changed: Alpha Raises Reduction LMR (instead of depth reduction).
• Changed: Only update pv when pv-node. Removed update pv in quiescence search.
• Changed: Time management.
• Changed: TT structure and entry replacement strategy.
• Changed: Lots of minor search algorithm details.
• Changed: Prefetch TT for a slight speed boost.
• Changed: Mate scores (in whole moves) in uci output. Not sure yet if I like it.
• Removed: Reward or punish captures in quiescence search.
• Removed: Code that we do not need (yagni).
• Failed experiments: Bad bishop eval, draw avoiding behaviour.
• Bug solved: Terrible one: qsearch comparing a zero score with TT score instead of the eval.
• Bug solved: Parsing negative time.
• Refactors: Attempt to centralize all scoring logic in scoring.zig, hce terms in 1 struct, most search vars in 1 struct.
• Note: I added a last-minute change in endgame.zig.

Chessnix 1.3 vs other engines:

Grail 1.0.2	6.5/10	+3	10 games
Gyatso 1.0.0	2/2	+2	2 games
Grail 1.0.0	1.5/2	+1	2 games
Caligula 3.0	1.5/2	+1	2 games
Knightx 4.7	1/2	+0	2 games
Critter 1.6a	1/2	+0	2 games
Myrddin 0.94	1/2	+0	2 games
Jackychess 25.12 JA	1/2	+0	2 games
4kc	1/2	+0	2 games
Sturddle 2.4.0	0.5/2	-1	2 games
Grail 1.0.1	0.5/2	-1	2 games
Petrel 3.1 JA	0/2	-2	2 games
Halogen 15.26.0	0/2	-2	2 games
Cinder 0.4.0	0/2	-2	2 games
Reckless 0.9.0 dev-0dd5b9ac	0/2	-2	2 games
Quirky 2.1 JA	0/2	-2	2 games
Prelude 2.1	0/2	-2	2 games
Reckless 0.9.0-dev-c5af2cea	0/2	-2	2 games
Caissa 1.24 JA	0/2	-2	2 games
Tcheran 9.0	0/2	-2	2 games
Prune 3.0.0	0/2	-2	2 games

Chessnix 1.4 download