I will add the wayback link below instead, because it has same content as above, except that the css file is saved with it too.Guenther wrote:Thanks! Never heard of this one, Tony.tmokonen wrote:Hmm, seems that an engine called DirtyBit, by Andrew Backes, has been overlooked:
https://github.com/andrewbackes/dirty-bit/releases
I played a bit with the latest release. It's a fixed hash size, about 775 MB. I've only run a few test games with it:
4-0-0 versus Isa (2186 ELO)
3-0-0 versus EveAnn (2337 ELO)
1-4-1 versus Ethereal (2631 ELO)
So anyway, I guess we get a very rough ballpark estimate of its strength.
It had its own web page at one point, but it is now only viewable through the Wayback Machine:
http://web.archive.org/web/201603121230 ... y-bit.com/
http://web.archive.org/web/201601110154 ... y-bit.com/
It seems the author was very interested to get a rating at CCRL, but strangely he never announced a release somewhere, except at the later created github site in 2015/06?
@Graham: did he ever try to contact CCRL before he stopped working on Dirty-Bit?
Dirty-Bit archived website wrote: About Dirty-Bit
Current Features
- Project Goals
Engine:
★ Goal: Create a program that plays legal chess using bitmap based internal data structure to represent the gamestate.
★ Goal: Create a program that can beat other chess playing programs, namely Exacto 0.d.
☆ Goal: Obtain a CCRL rating of at least 2000 ELO.
☆ Goal: Play at the Master level. I am estimating this to be approximately 2300 ELO on the CCRL scale.
☆ Goal: Rank within the top 100 programs on CCRL.
Dirty-Bit has most well known search heuristics and techniques in its code. However, some of the features still require tuning and have been disabled.
Change Log
- Enabled Features:
Principle Variation Search (PVS)
Quiescent Search (with delta pruning)
Null-Move Pruning
Late Move Reductions
Piece Square Tables
Search Extensions
MVV/LVA
Static Exchange Evaluation
Hash Tables (Transposition Table and Pawn Table)
Iterative Deepening
Internal Iterative Deepening
Aspiration Windows
Magic Bitboards (9 bit / 12 bit)
Lazy move generation[/code]
Disabled Features:
Killer Moves - Currently corrupts the move list
Futility Pruning - Somehow increases nodes search!?
Planned Features
Other than tuning the above disabled features, the following need to be implimented before release:
Multithreaded Search (DTS)
More elaborate evaluation
These features will most likely be added after release since they will not be used in CCRL games:
Pondering
Opening Book
Positional Learning
Code: Select all
0.37 9-12 Magics More eval tweaks added movestogo (UCI) command to go() 0.36 Mobility eval 0.35 Pawn Hash Tables and more pawn eval. 0.31 R=3 0.3 Rewritten LMR (set to 4/3) Killers disabled (since they are buggy at the moment) Rewritten SEE (SEE3, set for ALL captures, not just non-winners) Still using Check extensions 0.25 SEE and move ordering changes IID implimented, but disabled (needs tuning!) Time control fixes Check extensions 50 move rule bug fixed LMR disabled 34 cp for apsiration window 0.2 Rewritten fail hard PVS using nextmove() LMR above ply 4 and below move 5 Aspiration window of 50, fails expand by 100 then go infinite Simple Eval No check extensions No to move bonus 0.12 No Check extensions, no LMR (Changed move list to use NextMove() and lazy killers) 0.11 Check extensions 0.1 Lazy movegen PVS + killer moves Aspiration windows Simple eval: material and PSTs No check extensions, no LMR 0.01 Plays legal chess