v0.2.2

[0.2.2] - 2026-03-23

Added

• Added Bullet bootstrap and runner utilities to make NNUE training setup more repeatable.

Changed

• Moved the engine to a stronger embedded NNUE setup with SYKNNUE3 support, retained SYKNNUE2 compatibility, and shipped a much larger network.
• Reworked search internals with a static evaluation stack, pruning cleanups, SIMD-oriented NNUE updates, and harder SMP synchronization.
• Refreshed the README and release/testing documentation around NNUE workflows and regression checks.

Fixed

• Fixed a pruning regression after an Internal Iterative Reduction experiment was reverted.
• Fixed king-bucket perspective handling in NNUE evaluation.
• Fixed CI tag resolution and release-test workflow behavior.

v0.2.1

[0.2.1] - 2026-03-02

Added

• First release with NNUE support in the shipped engine.
• Added a full Texel tuning toolchain, including a native tuner, dataset builders, large-run orchestration scripts, and parameter application helpers.
• Added gensfen, Lichess PGN extraction, and parallel self-play tooling for generating NNUE training data.
• Added incremental NNUE accumulator support in search to make embedded NNUE practical during play.

Changed

• Made embedded NNUE the default evaluator and shipped the first successful SYKNNUE2 network with updated training/export scripts.
• Retuned the classical evaluator with Texel-generated parameters, updated mobility tables, and cleanup across evaluation utilities.
• Expanded the README to describe engine features, tuning, and NNUE workflows in more operational detail.

Fixed

• Fixed search history handling so the current position is tracked correctly for repetition logic.
• Hardened dataset generation, Stockfish annotation retries, and cross-platform script behavior.
• Tightened option handling and parameter extraction in evaluation/tuning utilities.

v0.1.0

[0.1.0] - 2026-02-17

Added

• First tagged release of the Zig-based Sykora UCI engine.
• Added the core engine stack: bitboards, magic move generation, legal move validation, perft/divide tooling, alpha-beta search, transposition tables, and clock-aware search control.
• Added a classical evaluation pipeline with pawn-structure, mobility, king-safety, and endgame terms.
• Added developer tooling for STS, self-play, benchmark/NPS runs, history tracking, automated tuning, and Lichess bot play/challenges.
• Added multi-target GitHub release automation for shipping binaries across Linux, macOS, and Windows.

Changed

• Improved move generation, hashing, undo support, null-move handling, repetition detection, and search heuristics throughout the initial development cycle.
• Expanded project documentation to cover engine usage, testing, tuning, and experiment history.
• Broadened build support for additional CPU architectures and optimized release build commands.

Fixed

• Fixed castling, en passant, capture handling, move legality edge cases, transposition-table scoring issues, and early search stability problems.
• Fixed cleanup and shutdown behavior around search threads, bot sessions, and Zig 0.16 compatibility.