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============================== My email: jotes@go2.pl



Chess engine: Willow 2.9

 

Willow - UCI engines   Rating CEDR=2941
A chess engine I am currently working on, written in C (WORK IN PROGRESS)
Compiled in Windows, works on BanksiaGUI with limited UCI support right now.

v.2.9:
Willow 2.9 is finally out! Estimated ELO: ~3000 CCRL

Almost all changes in 2.9 have been in evaluation.

Retuned all evaluations on a new dataset of 7m top engine games - found at https://github.com/analog-hors/tantabus
Lots of pawn evaluations - protected passed, candidate passed, phalanx, blocked, pawns near enemy king.
Changed the piece-square table implementation to one that is 4-king buckets based on the side of the board that both kings are on.
Forward mobility
King safety tables are now indexed based on pawn protection, with additional bonuses for pieces near enemy king.
Improved scaling and tempo bonus
A couple non-eval changes:

Changing time management to use nodes spent on best move
changing compiler to clang.
Score of Willow 2.9 vs Willow 2.8:

ELO   | 170.59 +- 8.62 (95%)
CONF  | 60.0+0.60s Threads=1 Hash=128MB
GAMES | N: 5000 W: 2889 L: 614 D: 1497


Willow rating progress:
Pl Engine Rating Score Games %
793 Willow 2.8 2941.0 48.00 186 25.81
925 Willow 2.7 2712.7 39.00 123 31.71
1170 Willow 2.5.11 2273.1 10.00 51 19.61
1243 Willow 2.6 2095.7 13.00 186 6.99

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