17

Changes

• Added pawn contextual piece square tables
• Added internal iterative reductions
• Added aspiration windows
• Improved pawn structure tables by considering rank of pawns
• Optimized evaluation parameter optimization
• Tuned history heuristic
• Tuned nullmove, futility, and late move reductions
• Tuned check and passed pawn extensions
• Tuned PVS
• Added "passed pawn is moveable" evaluation parameter
• Added "piece attacking other piece" evaluation parameter
• More training data
• Implemented proper MultiPV support
• Added UCI option go nodes
• Made code more beautiful

196 ±14 Elo in selfplay vs Nalwald 16 at 10s+0.1s.
Likely more than 50 Elo better against other engines.

Use the modern binaries if your CPU supports BMI2 and POPCOUNT.

Intel CPUs including and after Haswell (2013) support BMI2 and POPCOUNT.
AMD CPUs including and after Zen 1 (2017) support BMI2 and POPCOUNT.