v2.0.0 - Search and evaluation improvements

The next release of byte-knight! This release sees improvements in both search and evaluation as well as some bug squashing. Overall ~250/265 elo gain for STC/LTC respectively over v1.0.0.

Search

• Implemented principle variation search
• History heuristic with history gravity
• Aspiration windows
• Reverse futility pruning

Evaluation

• Re-scaled and fixed minor issues related to MVV-LVA move ordering scoring
• Re-wrote most of the evaluation implementation
• Added an HCE tuner
• Tuned PSQT values for the engine using the lichess-big-3 data set

Other changes and fixes

• Fixed a bug related to king captures
• Moved to Rust 2024 (stable)
• Improved CI and added ability to generate code coverage metrics (integrated with CodeCov)
• Updated dev dependencies (mostly suggested by Dependi)

Comparison to 1.0.0

STC

Elo   | 251.95 +- 12.77 (95%)
Conf  | 8.0+0.08s Threads=1 Hash=16MB
Games | N: 3006 W: 2102 L: 238 D: 666
Penta | [6, 52, 245, 472, 728]
https://pyronomy.pythonanywhere.com/test/1831/

LTC

Elo   | 264.99 +- 18.94 (95%)
Conf  | 40.0+0.40s Threads=1 Hash=128MB
Games | N: 1500 W: 1070 L: 106 D: 324
Penta | [5, 24, 100, 244, 377]
https://pyronomy.pythonanywhere.com/test/1832/

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These release notes are auto-generated by Github.

What's Changed

• chore: minor tweaks by @DeveloperPaul123 in #38
• feature: fast modulo for tt indexing by @DeveloperPaul123 in #39
• feat: principal variation search by @DeveloperPaul123 in #45
• fix: compare best to correct alpha by @DeveloperPaul123 in #46
• chore: simplify mvv-lva calculation by @DeveloperPaul123 in #47
• chore: rescale mvv-lva (again) by @DeveloperPaul123 in #48
• fix: mvv-lva scaling and minor issue with scoring for king captures by @DeveloperPaul123 in #49
• feat: add history heuristic by @DeveloperPaul123 in #50
• feat: use history gravity formula for history bonus by @DeveloperPaul123 in #51
• feat: implement aspiration windows by @DeveloperPaul123 in #53
• chore: re-write evaluation in preparation for tuning by @DeveloperPaul123 in #58
• chore: update deps and move to rust 2024 by @DeveloperPaul123 in #59
• fix: properly scaling eval and perspective by @DeveloperPaul123 in #65
• feat: tune on lichess big 3, from 0, 100k epochs by @DeveloperPaul123 in #66
• feat: add reverse futility pruning by @DeveloperPaul123 in #67
• feat: rework just file and add code coverage generation by @DeveloperPaul123 in #73

Full Changelog: v1.0.0...v2.0.0