stellar

Null Move Pruning

2 files changed, 14 insertions(+), 1 deletions(-)

diff --git a/ CMakeLists.txt b/ CMakeLists.txt

@@ -3,7 +3,7 @@ set(CMAKE_EXPORT_COMPILE_COMMANDS ON) project( Stellar

VERSION 0.0.13

VERSION 0.0.14

DESCRIPTION "Chess engine written in C" HOMEPAGE_URL https://git.dimitrijedobrota.com/stellar.git LANGUAGES C

diff --git a/ src/engine/engine.c b/ src/engine/engine.c

@@ -16,6 +16,7 @@ #define MAX_PLY 64 #define FULL_DEPTH 4 #define REDUCTION_LIMIT 3

#define REDUCTION_MOVE 2

#define INFINITY 50000 #define WINDOW 50

@@ -151,6 +152,18 @@ int negamax(Stats *stats, const Board *board, int alpha, int beta, int depth) { if (isCheck) depth++; Board copy;

if (depth >= 3 && !isCheck && stats->ply) {

board_copy(board, &copy);

board_side_switch(&copy);

board_enpassant_set(&copy, no_sq);

int score = -negamax(stats, &copy, -beta, -beta + 2,

depth - 1 - REDUCTION_MOVE);

if (score >= beta) return beta;

}

MoveList list; move_list_generate(&list, board);