Playing

Playing

Build

cd src
make                                                 # cc
make CC=/usr/vac/bin/xlc CFLAGS="-O2 -qlanglvl=ansi" # IBM XL C
make CC=gcc CFLAGS="-O2 -ansi"                       # GCC

There is also a make check target that runs a repetition regression test and the perft suite.

Command line (UCI)

Lite Blue speaks UCI, the standard engine interface:

printf 'position startpos moves e2e4 e7e5\ngo depth 8\nquit\n' | ./liteblue

The move is the bestmove line. go takes depth, movetime, wtime/btime (with increments), nodes or infinite; setoption name Hash value <MB> resizes the transposition table.

Interactive

./tui gives a terminal board: type a move (e2e4, e7e8q to promote), or d, undo, new, go, time <ms>, quit.

Self-play

./arena 500 40 plays the engine against itself — 500 ms a move, up to 40 plies.

In a browser

A 3D board front end runs at https://obsidian.nfinit.systems/liteblue/. The front end is by Claude Opus 5.5; the board and pieces were rendered on the machine's own Matrox graphics card.