VietCoffee 1.0.8 JA - new version chess engine

VietCoffee a chess engine written in Go, tuned to play aggressively. Zero dependencies, stdlib only. VietCoffee speaks the UCI protocol for use with chess GUIs, and includes a built-in Lichess Bot API client for playing live games on lichess.org. Github: https://github.com/williamvietnguyen/vietnamesecoffee/releases

Author: William Nguyen

Maximum Aggression Tuning

Every king-attack-related eval parameter has been cranked up. The engine will sacrifice material far more aggressively to get at the king.

Changes

• Tropism weights — knights/queens 3→5, bishops/rooks 2→4 per step closer to enemy king
• Outer zone bonuses — knights +5→+10, bishops/rooks +8→+15, queens +12→+20
• King attack weight table — ~1.5x across the board (e.g. 3 attackers: 240→360, 4 attackers: 540→750)
• Imbalance divisor — 200→120 (much steeper quadratic scaling when one side has a king attack edge)
• X-ray bonuses — bishop 25→40, queen diagonal 30→45, queen rank/file 20→30
• Uncastled king penalty — 30→50 mg
• Pawn shield penalty — 10→15 per missing shield pawn
• Pawn storm — 20→30 per rank, opposite-side castling multiplier 1.5x→2x
• Rook near king — open file +25→+35, semi-open +15→+25, doubled +25→+35
• Own pawn discount — 90→80 (even cheaper to sacrifice pawns for open lines)

Jim Ablett compiles:

VietCoffee 1.0.8 JA download