New version chess engine: Tcheran 4.1

 

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.

v.4.1:

Add tablebase probing in search based on 'fathom' (18.97 +- 8.35 (5-man))

Use arrayvec for PrincipalVariation (15.52 +- 8.72)

Fix an accidental fail hard in quiescence - fail soft when eval >= beta (12.54 +- 7.15)

Add futility pruning (10.82 +- 6.41)

Pack Move into u16 and store extra information, e.g. if the move is a capture (7.03 +- 4.89)

Add tablebase support and follow tablebase lines (6.79 +- 4.59 (5-man vs none))

Add an evaluation bonus for having a pair of bishops (4.35 +- 3.46)

Add countermove history (2.66 +- 2.03)

Use separate functions for scoring tacticals vs. quiets (2.64 +- 4.43)

Enable LTO (2.09 +- 3.32)

Pre-compute move flags (2.07 +- 4.01)

LMR: Reduce in check, but reduce less than normal (1.51 +- 2.70)

Use arrayvec for MoveList (1.05 +- 3.35)

Misc

Allow sending only 'go wtime' or 'go btime'

Avoid constructing Move objects directly where possible, preferring to extract them from MoveList

Hide the internal implementation details of Move

Add a ByPlayer struct for easily working with values stored for both players

Tcheran 2.5 - results:

Opponent	Score	+-	Games
Oxidation 0.7.2	5/8	+2	8 Games
Schoenemann 0.2.0	3/8	-2	8 Games
Rengar 2.0.0	1/8	-6	8 Games
4ku 5.1	0/8	-8	8 Games
Radiance 3.3	6/6	+6	6 Games
CT800 1.46	1/6	-4	6 Games
Knightx 4.11	0.5/6	-5	6 Games
Cwtch 1	0.5/6	-5	6 Games
Integral v4	0/6	-6	6 Games
Amelia 0.12	2/2	+2	2 Games
Nectar 0.1.7	2/2	+2	2 Games
StoneChess 2024-09-13	2/2	+2	2 Games
Heimdall 1.0 JA	0/2	-2	2 Games
Fidelio 17 MPV	0/2	-2	2 Games
Fidelio 17	0/2	-2	2 Games
Patricia 3.1	0/2	-2	2 Games
Rems 150824	0/2	-2	2 Games
Rems MPV Sep24	0/2	-2	2 Games
Rems Sep24	0/2	-2	2 Games
Roc 2024Aug24	0/2	-2	2 Games
RubiChess 20240817	0/2	-2	2 Games

 

Tcheran 4.1 download

Sample game from the Tcheran 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