v4.0.0: Search and eval improvements galore

[ptsouchlos]

This release was long overdue and represents a significant improvement over v3.0.0. Many new evaluation and search features have been implemented along with bug fixes and significant refactors and architectural changes. Based on the comparison to the previous release, I estimate v4.0.0 of byte-knight to be around ~2750-2800 ELO.

STC versus v3.0.0

Elo   | 438.94 +- 13.65 (95%)
Conf  | 8.0+0.08s Threads=1 Hash=16MB
Games | N: 5020 W: 4335 L: 58 D: 627
Penta | [0, 4, 82, 567, 1857]

LTC versus v3.0.0

Elo   | 431.08 +- 16.65 (95%)
Conf  | 40.0+0.40s Threads=1 Hash=128MB
Games | N: 3000 W: 2558 L: 21 D: 421
Penta | [1, 1, 32, 392, 1074]

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The following release notes are auto-generated.

What's Changed

• feat: implement support for isolated pawns by @ptsouchlos in feat: implement support for isolated pawns #159
• chore: project restructure by @ptsouchlos in chore: project restructure #161
• fix: qsearch conditions by @ptsouchlos in fix: qsearch conditions #164
• feat: make perft part of the main engine binary by @ptsouchlos in feat: make perft part of the main engine binary #162
• fix: lmr calc by @ptsouchlos in fix: lmr calc #165
• fix: bug with where we ignore draws by @ptsouchlos in fix: bug with where we ignore draws #169
• chore(deps): bump csv from 1.3.1 to 1.4.0 by @dependabot[bot] in chore(deps): bump csv from 1.3.1 to 1.4.0 #177
• chore(deps): bump clap from 4.5.48 to 4.5.53 by @dependabot[bot] in chore(deps): bump clap from 4.5.48 to 4.5.53 #179
• chore(deps): bump indicatif from 0.18.0 to 0.18.3 by @dependabot[bot] in chore(deps): bump indicatif from 0.18.0 to 0.18.3 #178
• chore(deps): bump criterion from 0.7.0 to 0.8.0 by @dependabot[bot] in chore(deps): bump criterion from 0.7.0 to 0.8.0 #180
• chore(deps): bump actions/upload-artifact from 5 to 6 by @dependabot[bot] in chore(deps): bump actions/upload-artifact from 5 to 6 #182
• chore(deps): bump actions/cache from 4 to 5 by @dependabot[bot] in chore(deps): bump actions/cache from 4 to 5 #181
• chore(deps): bump console from 0.16.1 to 0.16.2 by @dependabot[bot] in chore(deps): bump console from 0.16.1 to 0.16.2 #183
• chore(deps): bump clap from 4.5.53 to 4.5.54 by @dependabot[bot] in chore(deps): bump clap from 4.5.53 to 4.5.54 #184
• chore: refactor attacks and other parts of chess crate by @ptsouchlos in chore: refactor attacks and other parts of chess crate #185
• feat: integrate attacks and rays mods into move gen by @ptsouchlos in feat: integrate attacks and rays mods into move gen #186
• chore: update GitHub username by @ptsouchlos in chore: update GitHub username #187
• chore(deps): bump colored from 3.0.0 to 3.1.1 by @dependabot[bot] in chore(deps): bump colored from 3.0.0 to 3.1.1 #190
• fix: do not search positions w/no legal moves by @ptsouchlos in fix: do not search positions w/no legal moves #191
• chore(deps): bump thiserror from 2.0.17 to 2.0.18 by @dependabot[bot] in chore(deps): bump thiserror from 2.0.17 to 2.0.18 #192
• feat: add bishop pair bonus by @ptsouchlos in feat: add bishop pair bonus #194
• feat: add king safety evaluation by @ptsouchlos in feat: add king safety evaluation #196
• fix: release artifact naming by @ptsouchlos in fix: release artifact naming #199
• chore: remove PEXT by @ptsouchlos in chore: remove PEXT #198
• chore(deps): bump clap from 4.5.54 to 4.5.56 by @dependabot[bot] in chore(deps): bump clap from 4.5.54 to 4.5.56 #203
• chore: move engine cli to it's own folder by @ptsouchlos in chore: move engine cli to it's own folder #205
• chore(deps): bump criterion from 0.8.1 to 0.8.2 by @dependabot[bot] in chore(deps): bump criterion from 0.8.1 to 0.8.2 #206
• chore(deps): bump clap from 4.5.56 to 4.5.57 by @dependabot[bot] in chore(deps): bump clap from 4.5.56 to 4.5.57 #208
• chore(deps): bump anyhow from 1.0.100 to 1.0.101 by @dependabot[bot] in chore(deps): bump anyhow from 1.0.100 to 1.0.101 #207
• fix: remove binary by @ptsouchlos in fix: remove binary #214
• chore: simplify rand usage by @ptsouchlos in chore: simplify rand usage #210
• chore: update scripts and add more failure data by @ptsouchlos in chore: update scripts and add more failure data #215
• chore: make opposite a member function by @ptsouchlos in chore: make opposite a member function #213
• chore(deps): bump indicatif from 0.18.3 to 0.18.4 by @dependabot[bot] in chore(deps): bump indicatif from 0.18.3 to 0.18.4 #218
• chore(deps): bump clap from 4.5.57 to 4.5.58 by @dependabot[bot] in chore(deps): bump clap from 4.5.57 to 4.5.58 #217
• fix: properly reset half move clock by @ptsouchlos in fix: properly reset half move clock #220
• feat: add threats to eval by @ptsouchlos in feat: add threats to eval  #219
• fix: pvs logic by @ptsouchlos in fix: pvs logic #221
• chore: disable pv assertions by @ptsouchlos in chore: disable pv assertions #222
• fix: differentiate scores for mates and "infinity" by @ptsouchlos in fix: differentiate scores for mates and "infinity" #223
• chore(deps): bump clap from 4.5.58 to 4.5.60 by @dependabot[bot] in chore(deps): bump clap from 4.5.58 to 4.5.60 #229
• chore(deps): bump anyhow from 1.0.101 to 1.0.102 by @dependabot[bot] in chore(deps): bump anyhow from 1.0.101 to 1.0.102 #228
• fix: make min mate ply relative not depth relative by @ptsouchlos in fix: make min mate ply relative not depth relative #230
• fix: only store tt move if valid by @ptsouchlos in fix: only store tt move if valid #232
• fix: use ply in qsearch by @ptsouchlos in fix: use ply in qsearch #231
• fix: make tt score look up and compare ply independent by @ptsouchlos in fix: make tt score look up and compare ply independent #244
• feat: implement razoring by @ptsouchlos in feat: implement razoring #225
• chore(deps): bump actions/upload-artifact from 6 to 7 by @dependabot[bot] in chore(deps): bump actions/upload-artifact from 6 to 7 #245
• fix: properly handle check in qsearch by @ptsouchlos in fix: properly handle check in qsearch #247
• fix: double node counting in tt cutoff by @ptsouchlos in fix: double node counting in tt cutoff #249
• chore: separate UCI loop from engine struct by @ptsouchlos in chore: separate UCI loop from engine struct #243
• feat: implement mate distance pruning by @ptsouchlos in feat: implement mate distance pruning #248
• feature: implement piece mobility evaluation by @ptsouchlos in feature: implement piece mobility evaluation #250
• feat: tempo bonus for HCE by @ptsouchlos in feat: tempo bonus for HCE #251
• chore: add bench command for tuner by @ptsouchlos in chore: add bench command for tuner #254
• feat: add rook open/semi open file evaluation by @ptsouchlos in feat: add rook open/semi open file evaluation #253
• chore: add new failure data by @ptsouchlos in chore: add new failure data #256
• feat: improve hce-tuner performance by @ptsouchlos in feat: improve hce-tuner performance #257
• feat: add stop handling in tuner by @ptsouchlos in feat: add stop handling in tuner #259
• feature: king pawn shield and storm eval by @ptsouchlos in feature: king pawn shield and storm eval #258
• feature: add killers for move ordering by @ptsouchlos in feature: add killers for move ordering #261
• chore: remove bb while loops by @ptsouchlos in chore: remove bb while loops #260
• chore(deps): bump clap from 4.5.60 to 4.6.0 by @dependabot[bot] in chore(deps): bump clap from 4.5.60 to 4.6.0 #264
• chore(deps): bump shadow-rs from 1.7.0 to 1.7.1 by @dependabot[bot] in chore(deps): bump shadow-rs from 1.7.0 to 1.7.1 #263
• chore(deps): bump console from 0.16.2 to 0.16.3 by @dependabot[bot] in chore(deps): bump console from 0.16.2 to 0.16.3 #262
• chore: remove MoveGenerator struct and refactor movegen by @ptsouchlos in chore: remove MoveGenerator struct and refactor movegen #269
• feat: track seldepth in search by @ptsouchlos in feat: track seldepth in search #271
• feat: implement hashfull for tt table by @ptsouchlos in feat: implement hashfull for tt table #272
• chore: staged movegen with a fix in qs by @ptsouchlos in chore: staged movegen with a fix in qs #273
• chore: improve benchmark setup for chess crate by @ptsouchlos in chore: improve benchmark setup for chess crate #276
• chore: refactor move to be 16 bit by @ptsouchlos in chore: refactor move to be 16 bit #277
• feat: compress tt entry size by @ptsouchlos in feat: compress tt entry size #278
• feat: tt buckets with aging by @ptsouchlos in feat: tt buckets with aging #279
• chore: add new failure test data by @ptsouchlos in chore: add new failure test data #280
• feat: implement tt prefetch by @ptsouchlos in feat: implement tt prefetch #281
• chore: remove inclusive loop by @ptsouchlos in chore: remove inclusive loop #284
• chore: refactor board representation by @ptsouchlos in chore: refactor board representation #283
• chore(movegen): refactor movegen to support tacticals by @ptsouchlos in chore(movegen): refactor movegen to support tacticals #285
• chore: tweak lmp params and add start of tunable params by @ptsouchlos in chore: tweak lmp params and add start of tunable params #291
• chore: update readme and add dataset by @ptsouchlos in chore: update readme and add dataset #293
• chore(deps): bump codecov/codecov-action from 5 to 6 by @dependabot[bot] in chore(deps): bump codecov/codecov-action from 5 to 6 #295
• feat: initial try at a move picker by @ptsouchlos in feat: initial try at a move picker #294
• chore: update readme with move picker impl by @ptsouchlos in chore: update readme with move picker impl #297
• chore: move uci handler to engine cli by @ptsouchlos in chore: move uci handler to engine cli #298
• fix: better handling of epd line errors by @ptsouchlos in fix: better handling of epd line errors #300
• feat: add new "legal" module in chess crate by @ptsouchlos in feat: add new "legal" module in chess crate #301
• fix: tt hash pin checks by @ptsouchlos in fix: tt hash pin checks #302
• chore: interleaved tune, 4.9k epochs by @ptsouchlos in chore: interleaved tune, 4.9k epochs #303
• feat: add way to interleave data with hce-tuner by @ptsouchlos in feat: add way to interleave data with hce-tuner #304
• chore(deps): bump extractions/setup-just from 3 to 4 by @dependabot[bot] in chore(deps): bump extractions/setup-just from 3 to 4 #306
• chore(deps): bump toml from 0.8.23 to 1.1.2+spec-1.1.0 by @dependabot[bot] in chore(deps): bump toml from 0.8.23 to 1.1.2+spec-1.1.0 #307
• chore: refactor time control and search limits by @ptsouchlos in chore: refactor time control and search limits #310
• chore(deps): bump rand from 0.10.0 to 0.10.1 by @dependabot[bot] in chore(deps): bump rand from 0.10.0 to 0.10.1 #313
• chore(deps): bump softprops/action-gh-release from 2 to 3 by @dependabot[bot] in chore(deps): bump softprops/action-gh-release from 2 to 3 #312
• chore: adjust bestmove scaling by @ptsouchlos in chore: adjust bestmove scaling #311
• chore: refactor PVS to be easier to read by @ptsouchlos in chore: refactor PVS to be easier to read #315
• chore: no NMP with upper bound TT entry hits by @ptsouchlos in chore: no NMP with upper bound TT entry hits #316
• chore: first pass at SEE with qs SEE pruning by @ptsouchlos in chore: first pass at SEE with qs SEE pruning #317
• chore: minor readme and bench tweaks by @ptsouchlos in chore: minor readme and bench tweaks #319
• feat: move loop qs delta pruning by @ptsouchlos in feat: move loop qs delta pruning #320
• feat: split tactical moves into good/bad in move picker by @ptsouchlos in feat: split tactical moves into good/bad in move picker #318
• chore: add futility pruning by @ptsouchlos in chore: add futility pruning #322
• feat: check extensions by @ptsouchlos in feat: check extensions #324
• chore(deps): bump rayon from 1.11.0 to 1.12.0 by @dependabot[bot] in chore(deps): bump rayon from 1.11.0 to 1.12.0 #328
• chore(deps): bump clap from 4.6.0 to 4.6.1 by @dependabot[bot] in chore(deps): bump clap from 4.6.0 to 4.6.1 #326
• chore(deps): bump shadow-rs from 1.7.1 to 2.0.0 by @dependabot[bot] in chore(deps): bump shadow-rs from 1.7.1 to 2.0.0 #327
• fix: detect illegal ep when making moves by @ptsouchlos in fix: detect illegal ep when making moves #330
• chore: add failures documentation by @ptsouchlos in chore: add failures documentation #329
• fix: reject invalid EP squares when parsing FENs by @ptsouchlos in fix: reject invalid EP squares when parsing FENs #332

Full Changelog: v3.0.0...v4.0.0

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This discussion was created from the release v4.0.0: Search and eval improvements galore.