Tcheran 8.0 - new version chess engine

 

Tcheran - UCI chess engine  Author: Jonathan Gilchrist

Rating Chess Engines Diary CEDR=2242

If you want to know what the ranking of the Tcheran engine is, we encourage you to visit the website with the monthly updated CEDR ranking - RATING page.

Tcheran 8.0 what's new?

Network #7, upping the size to 384 hidden layer nodes with a fresh dataset generated using network #6 (62.36 +- 16.50)

Improve null move pruning reduction formula (29.37 +- 10.50)

Network #8, upping the size to 512 hidden layer nodes and trained with a larger 1B (unfiltered) FEN dataset (27.07 +- 9.95)

Network #9, upping the size to 768 hidden layer nodes and trained with an even larger 1B (after filtering) dataset and a WDL proportion of 0.4 (27.05 +- 9.85)

Add SEE pruning (25.45 +- 9.40)

Use history gravity and maluses (15.92 +- 7.40)

Do SEE when picking moves instead of when scoring moves (11.32 +- 6.27)

Compute checkers in make_move (8.03 +- 5.01)

Overwrite TT entries from old searches with static eval cache entries (7.85 +- 4.83)

Cache static eval of positions in the transposition table (5.05 +- 3.69)

Re-search with zero-window but full depth after raising alpha in a reduced-depth PVS search (2.83 +- 2.22)

Misc

Update the minimum Rust version to 1.91

Remove paste dev dependency

Remove arrayvec dependency

Simplify the move picker implementation

Simplify move scoring by removing sentinel values

Started tracking the bench in a '.bench' file which can be updated via 'just bench'

Fixed a datagen bug which caused non-decisive games to always be stored with an outcome of a loss for white

Switched to using 'tacticals' terminology for non-quiet moves

Improved 'd eval' command by showing piece contributions similar to Stockfish

Implement 'go nodes' command

Start adding a hash suffix to network files

Derive Copy for ZobristHash

Added a Rust implementation of OpenBench's SPRT algorithm

Bench depth was upped from 10 to 12

Author test:

Elo   | 168.06 +- 8.33 (95%)

Conf  | 8.0+0.08s Threads=1 Hash=16MB

Games | N: 4096 W: 2310 L: 470 D: 1316

Penta | [14, 104, 501, 886, 543]

Elo   | 182.37 +- 14.48 (95%)

Conf  | 40.0+0.40s Threads=1 Hash=128MB

Games | N: 1026 W: 572 L: 78 D: 376

Penta | [0, 10, 114, 274, 115]

Tcheran 5.1 vs other engines:

Fortuna 1.0 JA	4/4	+4	4 Partii
Aurora 20241007	2.5/4	+1	4 Partii
JudaS ++ 5.0	1/4	-2	4 Partii
ShashChess 38	0/4	-4	4 Partii
Alexander 4.0	0/4	-4	4 Partii
DarkSeid 5.2	0/4	-4	4 Partii
Artemis 6TR	0/4	-4	4 Partii
Lambergar 1.0	0/4	-4	4 Partii
Halcyon 1	2/3	+1	3 Partii
Chessplusplus 1.2.0	2/3	+1	3 Partii
Belette 3.0.0	0.5/3	-2	3 Partii
Zeta-Dva 0402 JA	2/2	+2	2 Partii
Albatros 1.0.0	2/2	+2	2 Partii
MadChess 3.2.2	2/2	+2	2 Partii
Zagreus 5.0	2/2	+2	2 Partii
Dinora 0.3.0	2/2	+2	2 Partii
Omelette 1.0 JA	2/2	+2	2 Partii
Camel 1.6.0	2/2	+2	2 Partii
StoneChess 2024-09-13	2/2	+2	2 Partii
Amy 0.9.6-pre AB JA	2/2	+2	2 Partii
Ssehc 1.0	2/2	+2	2 Partii

 

Tcheran 8.0 download

Tcheran engine top results:

Tcheran 5.0 wins Group E-12 (Amateur Section) Edition 08/2024, 2024.12.16-17

Sample batch of this engine:

[Event "2024.09.14.NewEnginesTest"] [Site "Chess Engines Diary"] [Date "2024.09.17"] [Round "1.32"] [White "Tcheran 3.0"] [Black "StoneChess 2024-09-13"] [Result "1-0"] [ECO "B00"] [PlyCount "72"] [EventDate "2024.??.??"] {[%evp 0,72,19,31,42,25,25,33,56,29,66,76,56,24,36,21,11,4,-5,-3,16,4,10,-56,-5,-36,-18,-61,-61,-18,-15,-1,7,3,-6,-10,5,-13,9,3,10,13,10,49,46,43,67,31,56,45,49,47,71,43,90,58,61,73,114,133,184,186,153,187,235,243,654,652,873,1006,2044,2497,29979,29984,29985]} 1. e4 Nc6 2. d4 d5 3. e5 f6 4. Nf3 g5 5. h3 Bg7 6. Bb5 Nh6 7. O-O O-O 8. Re1 g4 9. hxg4 Bxg4 10. Bxc6 bxc6 11. e6 Qd6 12. Qe2 Nf5 13. c3 c5 14. Qc2 Bxf3 15. dxc5 Qc6 16. Qxf5 Be4 17. Qh3 Qxc5 18. Be3 Qb5 19. Nd2 Bg6 20. b3 Qd3 21. Nf3 c6 22. Rac1 Qa6 23. a4 Rfb8 24. Nd4 Rb7 25. b4 Rc8 26. a5 c5 27. bxc5 Rxc5 28. Nb3 Rcb5 29. Nc5 Qxa5 30. Nxb7 Rxb7 31. Red1 Rc7 32. Qf3 Be4 33. Qxe4 Rxc3 34. Qb1 Rxc1 35. Qb8+ Bf8 36. Rxc1 h5 1-0