Halcyon 1

Elo gain vs Halcyon 0.3:

• STC (8s+0.08s): 234.4 +/- 15.9
• LTC (60s+0.6s): 326.8 +/- 18.6

Changelog:

• Hash moves
• Improved evaluation
  • Tuned weights
  • King safety
  • Pawn structure
    • Isolated pawns
    • Backward pawns
    • Doubled/tripled pawns
    • Passed pawns
  • Connected rooks
  • Open file control
• Insufficient material detection
• Transposition table is reset on ucinewgame
• Fixed mate score storage in transposition table
• Fixed compilation errors on some architectures
• Support popcnt/BMI2/AVX2/AVX-512 instructions

Halcyon 0.3

Elo gain vs Halcyon 0.2:

• STC (8s+0.08s): 315.0 +/- 17.4
• LTC (60s+0.6s): 270.0 +/- 15.4

Changelog:

• Transposition table
• Late move reduction
• Magic bitboards
• Improved move generation speed
• Tapered evaluation
• Contempt factor
• Increment is now considered
• Better overall time usage
• Bug fixes

Halcyon 0.2

Changelog:

• PV move ordering
• Killer heuristic
• Improved speed with time limit
• Aspiration window
• Zobrist hashing
• 3-fold repetition detection
• Miscellaneous bug fixes

Halcyon 0.1

Features include:

• Perft
• Negamax search
• Quiescence search
• MVV-LVA and piece-square move ordering
• Null move pruning

Supports enough of the UCI protocol to work on many GUIs and lichess-bot