Simbelmyne 1.10.0 JA - new version chess engine

 

Simbelmyne - UCI engine  Author:Sam Roelants

Rating Chess Engines Diary CEDR=2474 

v.1.10.0:

What's new

Version 1.10 is a pretty huge grab-bag of changes. Lots of re-factors that make

the codebase easier to maintain, a lot of search improvements, and — for

the first time in several versions — a big round of improvements to the

evaluation function. I think Simbelmyne is slowly but surely getting to the

point where a NNUE-based evaluation becomes inevitable, but let's see how far

we can take her, first!

No gauntlet just yet, so I don't have a very accurate guess at the playing

strength, but self play tests say +215 STC and +200 LTC.

Added features

🔍 Search

Add pawn based correction history (46+-13.62) (#261)

Non-pawn based correction history (19.73+-8.64) (#298)

Material based correction history (6.99+-4.69) (#300)

Don't clear countermoves between searches (2.96+-2.36) (#263)

Negative extensions (2.29+-1.59) (#262)

Multicut (3.84+-3.07) (#264)

Triple extensions (3.30+-2.64) (#265)

Remove History aging (6.85+-6.05) (#268)

Remove delta pruning (3.51+-4.55) (#283)

⚖️: Evaluation

Pawn cache table (18.57+-8.21) (#282)

Bonus for knight/bishop shelters (5.26+-3.88) (#286)

Bonus for safe check options (12.52+-6.66) (#284)

Bonus for unsafe check options (15.32+-7.39) (#285)

Penalty for bad bishops (16.14+-7.65) (#287)

Square rule for passed pawns (7.40+-4.83) (#294)

Endgame scaling (11.37+-6.17) (#296)

Bonus for free/unhindered passed pawns (8.73+-5.39) (#295)

Include attacked stop square in free passed pawn condition (6.36+-4.43) (#299)

Bonus for protected passed pawns (3.73+-2.97) (#297)

🐛 Bugfixes

Pass conthist table to move picker by value, instead of copy (11.69+-7.72)

(#256)

⌛ Time management

Better hard/soft time limits (22.08+-9.26) (#272)

Node based scaling of soft time limit (9.24+-5.53) (#273)

best_move stability scaling of soft time limit (9.83+-5.80) (#270)

Misc

Big refactor of the SPSA tuning architecture (#254, #255)

Big refactor of the search history (#257)

Big eval refactor (#274, #275, #278, #280, #281, #288, #292)

Normalized eval using a logistic WDL model (#259)

Shrink TT entries (16.38+-7.96) (#260)

Use TT eval in Quiescence search (4.81+-3.60) (#267)

Make mv.is_quiet() return true for all non-tacticals (24.67+-10.53) (#249)

See the respective PRs for self-play results where relevant

Choosing a binary

This release comes with precompiled binaries for all major platforms. Because

the engine benefits tremendously from more modern CPU instruction sets, there

are binaries compiled for major instruction sets, following the x86-64

microarchitecture levels

as a naming scheme.

Realistically, on modern hardware (< 10 years old), you should be okay to use the

binaries labeled V3. If the engine crashes within the first seconds, try V2,

and so on.

Simbelmyne 1.10.0 vs other engines:

Pedantic 2.0.0	4.5/12	-3	12 Games
Critter 1.6a	4.5/12	-3	12 Games
RubiChess 20240817	1/12	-10	12 Games
Molybdenum 4.0	1.5/10	-7	10 Games
Sloth 2.0	9/9	+9	9 Games
Mufasa 0.2.1 JA	9/9	+9	9 Games
Protej 0.6.7	9/9	+9	9 Games
Oxidation 0.7.2	4/4	+4	4 Games
Shallow 5	4/4	+4	4 Games
LizardBrain	4/4	+4	4 Games
CeeChess 1.4	4/4	+4	4 Games
Floyd 0.9 JA	4/4	+4	4 Games
Bitbit 1.2	3.5/4	+3	4 Games
Lux 4.2	3.5/4	+3	4 Games
Ice4 v5	3/4	+2	4 Games
Monty 20241209	2.5/4	+1	4 Games
Protej 20240811a	1.5/4	-1	4 Games
CT800 1.46	3/3	+3	3 Games
Patricia 3.1	1.5/3	+0	3 Games
Pioneer 0.3.2	2/2	+2	2 Games
Hedgehog 2.407	2/2	+2	2 Games

Jim Ablett compiles:

Simbelmyne 1.10.0 JA download