Improved gameplay (static eval. + null move pruning + move ordering)

What's Changed

• optimizations by @sictransit in #44

Full Changelog: v1.5.0...v1.6.0

NegaScout, history heuristics + bug fixes

An increase in strength thanks to the implementation of NegaScout and history heuristics, plus some bug fixes.

This is the result of a small tournament vs Stockfish 15 locked to ELO 2500. The current version is stronger than the previous. On my machine, it even a beats Stockfish 15 (at ELO 2500), but it's not a fair comparison since Stockfish seems to blunder to lower its strength.

Rank Name                          Elo     +/-   Games   Score    Draw 
   1 Woodpusher (1.5.0)             89     131      20   62.5%   35.0% 
   2 stockfish-windows-x86-64-avx2  35     145      20   55.0%   20.0% 
   3 Woodpusher (1.4.2)           -127     149      20   32.5%   25.0% 

SPRT: llr 0 (0.0%), lbound -inf, ubound inf
30 of 30 games finished.

Player: stockfish-windows-x86-64-avx2
   "Draw by 3-fold repetition": 3
   "Draw by insufficient mating material": 1
   "Loss: Black mates": 1
   "Loss: White mates": 6
   "Win: Black mates": 4
   "Win: White mates": 5
Player: Woodpusher (1.5.0)
   "Draw by 3-fold repetition": 5
   "Draw by adjudication: user decision": 1 (both sides had rook + king)
   "Draw by insufficient mating material": 1
   "Loss: Black mates": 2
   "Loss: White mates": 2
   "Win: Black mates": 3
   "Win: White mates": 6
Player: Woodpusher (1.4.2)
   "Draw by 3-fold repetition": 4
   "Draw by adjudication: user decision": 1 (both sides had rook + king)
   "Loss: Black mates": 6
   "Loss: White mates": 5
   "Win: Black mates": 2
   "Win: White mates": 2

What's Changed

• negascout by @sictransit in #43

Full Changelog: 1.4.2...v1.5.0

Refactored UCI interface (fixed stalling) + no illegal moves from the opening book.

What's Changed

• uci interface rewrite + fixed opening book (illegal move issue) by @sictransit in #40

Full Changelog: v1.4.1...1.4.2

don't lose on time if the opponent is allowed negative time

fixed negative time issue (#37)

* allow opponent to play on negative time
* bumped version

opening book with more options + fixed UCI command concurrency issue

new opening book with more options for each hash (#36)

* new opening books with more options for each hash
* fixed concurrency issue in UCI command handling, generating illegal moves
* bumped version

performance boost + correct 'matein' calculation

What's Changed

• bug fixes (matein) + performance boost by @sictransit in #32

Full Changelog: v1.2.1...v1.3.0

opening book is allowed per default

v1.2.1

bump version: 1.2.1

uci option toggle opening book usage

v1.2.0

uci option to toggle opening book usage

speed and accuracy

What's Changed

• reverted to JSON opening book by @sictransit in #27
• speed and accuracy improvements by @sictransit in #28

Full Changelog: v1.0.0...v1.1.0

major rewrite, optimization and bug fixes

This release should play a bit better, thanks to some bug fixes and better time management.

The README now contains some useful information as well.

What's Changed

• lots of long-forgotten changes, but they seem ok by @sictransit in #21
• net8.0 by @sictransit in #22
• major code cleanup, no multithreading, back to basics by @sictransit in #24
• move ordering + not dependant on uci movestogo by @sictransit in #25
• major rewrite + bug fixes by @sictransit in #26

Full Changelog: v0.9.5...v1.0.0