Berserk

[timetraveller]

by Jay Honnold

v1.2.2

Download

[timetraveller]

v2.0.0

Changes:
The largest changes that come from this release are evaluation changes. PSQT's dominated in 1.2.2, but that lead to poor pawn structure and poor king safety. This has been addressed in 2.0.0 with all PSQT's being flattened (more understandable human values) and specific evaluation parameters around pawn structure and king safety. Along with this, piece mobility has been added.
Estimated ELO ~2450
Download

[timetraveller]

v3.0.0

Changes
-Improved LMR
-Added LMP
-King Safety evaluation improvement
-Threat evalution
-SEE pruning in qsearch
-Aspiration window adjustments

https://github.com/jhonnold/berserk/releases/tag/3.0.0

[jearls]

v3.1.0

https://github.com/jhonnold/berserk/releases/tag/3.1.0

A bug fix version.

[timetraveller]

Berserk 3.2.0

https://github.com/jhonnold/berserk/releases/tag/3.2.0

[jearls]

v3.2.1

https://github.com/jhonnold/berserk/releases/tag/3.2.1

This is a small set of changes, very little Elo gain (all from additional tuning)

[EzioMagnifico]

Bersek 3.3.0 ( 10 April)

Download

Author: Jay Honnold

https://workupload.com/file/PZT3yXmU483

[EzioMagnifico]

Bersek 4.0.0 ( 27 April)

Thanks to the Author Jay Honnold

https://github.com/jhonnold/berserk/releases/tag/4.0.0

- SMP functionality added
- Various speed improvements
- King safety reverted to pre-3.3.0 implementation
- Endgame specific functionality ended
- KPK Bitbase (credit to Cheng)
- KXK knowledge
- Scale strong side scoring based on board state
- Tactical moves included in LMR
- Improvement on time management
- IID

[EzioMagnifico]

V 4.1.0
Thanks to the Author Jay Honnold jhonnold

https://github.com/jhonnold/berserk/releases/tag/4.1.0

Changes :
- Candidate Passed Pawns
- Various NPS Improvements (22% increase!)
- Caching "special piece" bitboard
- Incremental material updates
- Pawn hash tables
- PEXT support
- Pawn threats
- QS modified to rely purely on SEE scoring
- Credit to Halogen's author for this idea
- Syzygy Tablebase support added
- Using Andrew Grant's Pyrrhic

[EzioMagnifico]

Berserk 4.2.0
Thanks to the Author Jay Honnold

https://github.com/jhonnold/berserk/releases/tag/4.2.0

This is a huge dump of search and evaluation changes. Most of which present with minor Elo results. I estimate this to be 50-60 Elo stronger than Berserk 4.1.0.

Changes :

King safety pawn shelter tuned
LMR depth adjustment
2 -> 3
Using Ed's IIR instead of IID
Tuned reverse futility pruning cutoffs
[62,132,220...] -> [65,135,220,...]
Removed bad rook evaluation terms
Adjusted delta pruning cutoff
200 -> 150
Random draw values
Dragon Bishop (Long diagonal)
TT utilized in QSearch
Time adjusted to be around window expansions
Double singular extension (sf inspired)
Prob Cut
Pinned pieces in king safety
Recapture extension
History heuristic rewrite
Using a more standard formula rather than numerator/divisor
Late Move Pruning adjustments

Bugs :

Transposition table depth issue
Transposition table bucket issue
KPK

[EzioMagnifico]

Berserk 4.4.0
Thanks to the Author Jay Honnold

Download : https://workupload.com/file/NXwPAkML75U

v.4.4.0.

Counter move history and pruning
Follow up move history
History extension
Castle extension
Adjust depth on fail high in aspiration
Space eval cleanup
Credit to Laser for inspiring the resulting code which is MUCH nicer
Time management simplification
Berserk should be semi-aggressive, but nothing compared to what previous releases are

[EzioMagnifico]

Berserk 4.5.0
Thanks to the Author Jay Honnold :

Download : https://github.com/jhonnold/berserk/releases/tag/4.5.0

Changes :

UCI Ponder
UCI MultiPV
UCI searchmoves
Search tuning
Contempt
Dynamically based on score in position (originally implemented in SF)
Queen Evaluation Terms
Rook/Queen gun
Queen Opposite Rook
Rook Evaluation Terms
Rook value varies given # of open files
Rook bonus for being able to move to Open File
Threat Evaluation Terms
Pieces being able to threaten queen
Killer/Counter moves improvement in LMR
Check Extension improvement

[EzioMagnifico]

Berserk 4.5.1
Thanks to the Author Jay Honnold jhonnold

Download : https://github.com/jhonnold/berserk/releases/tag/4.5.1

[EzioMagnifico]

Berserk 4.6.0
Thanks to the Author Jay Honnold

Download : https://github.com/jhonnold/berserk/releases/tag/4.6.0

FRC support added
No change in elo from 4.5.1

[EzioMagnifico]

Berserk 6
Thanks to the Author Jay Honnold

Download : https://github.com/jhonnold/berserk/releases/tag/6

This is the first release of Berserk with a NNUE evaluation. The net was trained using a custom trainer from 350 million FENs from Berserk 5 self play games. Berserk currently uses a network arch that does not have compatibility with other engines.

The network is embedded into the binary. There is no option to disable it or attach another network. This will most likely change in the future.

ELO | 137.82 +- 5.35 (95%)
CONF | 40.0+0.40s Threads=1 Hash=64MB
GAMES | N: 10000 W: 4849 L: 1078 D: 4073
Note: These are results vs Berserk 4.5.1 and will not reflect this strongly against other engines

Choosing a binary
Binaries currently require popcnt.
Binaries without the label avx2 are compiled with SSE.
Binaries with the label pext require your processor to support bmi2.

Changes
Added NNUE
Thanks
I'd like to, once again, thank Connor McMonigle (Seer's author) for his guidance on NNs.
I'd like to also thank Zahak's author for assistance with net strength validation.