Bikjump V3.0 is now available for download

[abik]

Long overdue, since I have been working on and off on the new release for years now, but BikJump v3.0 is now availabe for download (Windows and Linux 64-bit; an Android chess engine package is still in the making):

BikJump v3.0 download page

The new features include:

• added all sources under git source control
• complete refactoring of BikJump sources
• various bug fixes, refinements, and cleanup
• much faster move generator
• search enhancements (better move ordering, LMR)
• fully revised the evaluation function
• multiply support
• added threading support (a start only)

The last release was v2.0.1 in 2008 (since then, I distributed untracked versions v2.1 and v2.5). This v3.0 replaces all previous versions. I made many improvements to the move generator, search, and evaluation function. Internal self-testing shows some strength improvements, but most importantly to me, the playing style had become a lot more attractive, more open and aggressive play. Multithreading support has started but it is a very primitive set up only for now, to be improved later. I strongly recommend simply testing the single-threaded version of v3.0 for the time being.

Looking forward getting feedback on this!

[Graham Banks]

Thanks. Do you have a rough estimate of strength for 3.0?

[abik]

Thanks. Do you have a rough estimate of strength for 3.0?

I have set up a rigorous self-playing testing infrastructure to see if new ideas help or hurt with the strength (in the past I would more often just "wing" it). Based on that, I am hopeful that v3.0 is about +100ELO compared to v2.0.1. But.... self-testing is notorious bad in computing ratings, so hopefully we get some tournament play in soon.

[Graham Banks]

Thanks. Do you have a rough estimate of strength for 3.0?

I have set up a rigorous self-playing testing infrastructure to see if new ideas help or hurt with the strength (in the past I would more often just "wing" it). Based on that, I am hopeful that v3.0 is about +100ELO compared to v2.0.1. But.... self-testing is notorious bad in computing ratings, so hopefully we get some tournament play in soon.

[Gabor Szots]

Very good news, Aart, and now I know which engine to test next.

[abik]

Very good news, Aart, and now I know which engine to test next.

Looking forward to that! I see BikJump v2.0.1 ratings between 2030 and 2100 on the various CCRL reportings, and am very curious where v3.0 lands. And I am already thinking on what to improve for v3.1

[OttoLau]

Thank you Aart, Bikjump has been a stable sparring partner for my engines while im developing them, and 3.0 seems very good! Looking forward to more updates

[abik]

Thank you Aart, Bikjump has been a stable sparring partner for my engines while im developing them, and 3.0 seems very good!

Thanks so much, Otto! I have heard from a few others too that they enjoy BikJump as stable sparring partner, and comments like that always make my day! Now on to making it actually stronger as well...

[Bart Weststrate]

Aart something wrong in Cutechess cli, it's about the pv sent:

C:\0_cutechess>del sm_sm_4_moves_book.pgn

C:\0_cutechess>cutechess-cli -concurrency 10 -srand 1942127704 -openings file=IM_4mvs.pgn order=sequential -engine name=SM_2182b cmd=00_2182b.exe proto=uci -engine name=Bikjump cmd=bikjump.exe proto=uci -each restart=on tc=60/20+1 -draw movenumber=100 movecount=5 score=70 -resign movecount=5 score=999 -rounds 250 -pgnout sm_sm_4_moves_book.pgn -repeat 2 -games 2
Started game 1 of 500 (SM_2182b vs Bikjump)
Started game 3 of 500 (SM_2182b vs Bikjump)
Started game 5 of 500 (SM_2182b vs Bikjump)
Started game 6 of 500 (Bikjump vs SM_2182b)
Started game 2 of 500 (Bikjump vs SM_2182b)
Warning: Illegal PV move % from Bikjump (10)
Warning: PV: Qa4+ Nc6 %
Warning: Illegal PV move % from Bikjump (2)
Warning: PV: cxd5 Nxd5 %
Warning: Illegal PV move % from Bikjump (2)
Warning: PV: Qa4+ Nc6 %
Started game 4 Warning: Illegal PV move %e2c4 from Bikjump (2)
of 500 (Bikjump vs SM_2182Warning: PV: Qe2 dxc4 %e2c4
b)
Warning: Illegal PV move %f6d5 from Bikjump (2)
Warning: PV: Qb3 e6 cxd5 %f6d5
Warning: Illegal PV move % from Bikjump (2)
Warning: PV: d3 dxc4 Qa4+ Nc6 Qxc4 %
Started game 7 of 500 (SM_2182b vs Bikjump)
Warning: Illegal PV move %b5d7 from Bikjump (2)
Warning: PV: cxd5 Nxd5 Bb5+ Bd7 Qh5 Nxc3 %b5d7
Warning: Illegal PV move %d4e5 from Bikjump (6)
Warning: PV: Ne5 Nbd7 d4 Nxe5 %d4e5
Warning: Illegal PV move %f6g4 from Bikjump (6)
Warning: PV: d3 Qb6 Ne5 Qd4 Nxg4 %f6g4
Warning: Illegal PV move % from Bikjump (6)
Warning: PV: d4 Nbd7 Nc3 Ne4 Nxe4 dxe4 %
Started game 9 of 500 (SM_2182b vs Bikjump)
Started game 8 of 500 (Bikjump vs SM_2182b)
Started game 10 of 500 (Bikjump vs SM_2182b)
Warning: Illegal PV move % from Bikjump (10)
Warning: PV: Bf4 Nc6 Be2 e5 dxe5 dxe5 Qxd8+ Kxd8 %
Warning: Illegal PV move % from Bikjump (18)
Warning: PV: Bb5+ Bd7 %
Warning: Illegal PV move %b7c6 from Bikjump (18)
Warning: PV: Bb5+ Bd7 Nc3 Nc6 Nxc6 %b7c6
Warning: Illegal PV move %d5c3 from Bikjump (2)
Warning: PV: d4 Nc6 cxd5 Nxd5 Qb3 Be6 Bc4 Nxd4 Qxb7 %d5c3
Warning: Illegal PV move % from Bikjump (2)
Warning: PV: d4 Nc6 cxd5 Nxd5 Bc4 Be6 Qa4 Nxc3 bxc3 Bxc4 %
Warning: Illegal PV move % from Bikjump (10)

We should get rid of the warnings.

[abik]

Aart something wrong in Cutechess cli, it's about the pv sent:

And with that goes my reputation for stability

Explanation: for my own understanding, I started to include quiescence moves for the PV after a non-standard % symbol, but since this is non UCI compliant, I should of course not ship that version. Let me push a non-version changing fix for that.

Are you most interested in Windows or Linux?