v1.0.0

Getting out from ZeroVer club now that these two conditions are met:

• Lynx has basically reached feature-parity with BBC, engine outcome of BitBoard Chess Engine in C YouTube playlist that helped me the most during the initial phases of Lynx development.
• .NET 8 GA has been released and therefore Lynx no longer relies on pre-release SDK or library versions.

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• 🔍 Rewrite NMP (#479, #482, #492, #493, #494)
• 🔍 In case of 'ponder-hit', research last depth (#466)
• 🔍 Don't clear TT move if no best move is provided: keep old one II (#478)
• ⚖ Use PSQTs tuned without explicit piece values (#425)
• ⚡ Incremental move sorting (#477)
• ⚡ Avoid checking lack of material in static evaluation when the phase is high enough (#490)

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Full Changelog: v0.19.0...v1.0.0

v0.19.0

• 🔍 Tune LMR reduction (#452)
• 🔍 PVS-LMR logic improvement (#456)
• 🔍 Implement TT in quiescence search (#308)
• 🔍 Don't clear TT move if no best move is provided: keep old one (#462)
• ⌛ Check _searchCancellationTokenSource in qsearch as well (#454)
• 🐛 Avoid storing the same move duplicated in both killer moves (#458)
• 🐛 Ensure no search depth 0 happens after a 'ponder hit' (#465)

Non-strength winning chnages:

• 🐛 Fix ucinewgame command when followed by go command (#455)

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Full Changelog: v0.18.0...v0.19.0

v0.18.0

• ⚖ Tune PSQT (#414, #415, #417)
• 🔍 Add razoring (#429)
• 🔍 Add soft cap history moves score (#442)
• 🔍 Revisit and improve Aspiration Windows (#437)
• ⚡ Implement PEXT bitboards for bishop and rook attacks (#451)
• 🐛 Fix evaluation when checkmate is delivered at the same time 50 moves rule apply (#453)
• 🐛 Fix move ordering at high depths/LTC (#448, indirectly #442)
• 🐛 Avoid re-searches in IDDFS (#439)

Non-strength winning changes:

• ⚖ Normalize eval and add UCI_ShowWDL option (#421, #422)
• 🧹 Remove UseOnlineTablebaseInSearch from UCI (#441)

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Full Changelog: v0.17.0...v0.18.0

v0.17.0

• ⚖ Add full PSQT and tapered evaluation (#379)

• ⚖ Add tapered bishop pair bonus (higher in endgames) (#390)

• 🔍 Add Reverse Futility Pruning (RFP) (#382)

• 🔍 If there's a single legal move, make it immediately (#401)

• ⌛ Add basic time management when MovesToGo are provided (#409)

• ⚡ Various .NET related perf improvements around .NET 8 new capabilities:

  • Improve position UCI command parsing (#410, #405), improve position
  • Improve other commands parsing (#411)
  • Use FrozenDictionarys where possible (#403)
  • Use C#12 collection literals (#393)

• 🐛 Fix UCI_EngineAbout string (#408)

Non-strength winning changes:

• Add printsettings option to print runtime settings Configuration.EngineSettings (#391)
• Re-Add hashfull in last UCI info command using an approx value (#394)
• Consolidate apple silicon binaries into osx-arm64 one, add linux-musl-x64 support (#412)

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Full Changelog: v0.16.0...v0.17.0

v0.16.0

• Use standard depth concept in NegaMax method (#377)
• ⚡ Remove UCI hashfull command for performance reasons (#342)
• ⚡ Force TT array to have a power of two length (#349)
• ⚡ TT entry struct alignment (#352)
• ⚡ Remove explicit hardware intrinsics usage (#343)
• ⚡ Optimize divisions by power of two (#350)
• ⚡ Avoid opposite side offset calculation (#345)
• ⚡ Add MoveGenerator.CanGenerateAtLeastAValidMove (#360)
• ⚡ Remove MoveGenerator methods from Position (extra indirection) (#367)
• ⚡ Check sliding pieces attacks last in IsSquaredAttacked (#369)
• 🐛 Fix IndexOutOfRangeException when ply >= MaxDepth (#348)
• 🐛 Check maxDepth when btime wtime or MoveTime go commands are provided (#361)

Non strength-winning changes:

• Make executables self-contained, without the need of appsettings.json (#362)
• Parse cli arguments and use them as UCI commands (#370)
• Add warning when invalid fen parsed (#357)
• Remove non ascii char from standard output (#373)
• Add OpenBench support (#339, #372)
• Add Mnps to perft and divide outputs (#351)
• 🐛 Fix perft divide (#347)

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Full Changelog: v0.15.0...v0.16.0

v0.15.0

• 🔍 Exclude promotions from killer moves and take them into account in move ordering (#302)

• 🔍 Enhance depth extension on check (#313)

• 🔍 Increase MaxDepth default value to 128 (#292)

• 🔍 Add ToggleBits method and use it in Make/Unmake moves (#324)

• 🔍 Replace !_isFollowingPV LMR condition with !pvNode (#312)

• ⚡ Move to .NET 8 (#291)

• ⚡ Implement make/unmake move instead of allocating a new Position (#321)

• ⚡ Avoid passing Game.CurrentPosition reference down search methods (#322)

• ⚡ Change threefold repetition detection to 2 repetition detection (#296)

• ⚡ Use Bmi1.X64.TrailingZeroCount and Popcnt.X64.PopCount hardware intrinsics (#330)

• ⚡ Don't reload config on file changes (#299)

• ⚡ Disable NLog autoreload (#329)

• ⚡ Make NLog targets async (#331)

• ⌛ Simplify time management (#288).
  This makes this release the first cutechess-friendly one, which means no timeouts when tested with short tc (10+0.1, 8+0.08, etc.)

• 🐛 Fix TT probing condition and TT moves score (#298)

Non strength-winning changes:

• 🐛 Fix nlog concurrency issue when accessing log files (#286)
• 🐛 Fix overflow that was causing negative hashfull numbers in uci info commands (#307)
• 🐛 Fix PV table bug which keeps extra moves in PV after the move where a draw is detected (#297)
• 🐛 Fix illegal moves potentially sent when the previous search line is hit (#294, #295)

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Full Changelog: v0.14.1...v0.15.0

v0.14.1

Non strength-winning changes:

• 🐛 Stop potentially sending uci info commands after bestmove one by (#284). This was making it a pain to use with cutechess-cli
• Add thread id to logs (#283)

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Full Changelog: v0.14.0...v0.14.1

v0.14.0

• 🔍 Add Transposition table (#274) and a variable to disable it (#278), although setting Hash to 0 also does the job

• 🔍⚖ Add support for lichess-hosted online tablebases (#273)

• 🔍 Increase search depth by one when in check (#275)

• ⚡ Convert Position into readonly struct and make use of in modifier (#258)

• ⚡ Remove interpolated logging (#268)

• ⚡ Early loop exit (#267)

• ⚡ Use [GeneratedRegex] attribute when possible (#269)

• 🐛 Fix PV Table size (#259)

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Full Changelog: v0.13.0...v0.14.0

v0.13.0

• 🐛⚖ Fix positional score of black queens (#212)
• ⚖ Improve pawn evaluation: doubled, isolated and passed pawn detection (#201)
• ⚖ Improve rook evaluation: open and semi-open files (#202)
• ⚖ Improve king evaluation: open and semi-open files and 'shield' bonus (#210)
• ⚖ Improve bishop and queen evaluation: mobility (#213)
• ⚖ Increase queen value from 9 to 10 pawns (#215)

Non strength-winning changes:

• Add support for macOS 12 Monterey running on ARM (#195)
• Add support for macOS 13 Ventura running on ARM (#214)

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Full Changelog: v0.12.0...v0.13.0

v0.12.0

• ⚖ Improve positional scores (#192)

Non strength-winning changes:

• 🐛 Fix evaluation trace logs (#193)

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Full Changelog: v0.11.0...v0.12.0