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fix: bug with where we ignore draws #169

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Merged
merged 1 commit into from
Nov 17, 2025
Merged

fix: bug with where we ignore draws #169

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12 changes: 6 additions & 6 deletions engine/src/search.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -425,11 +425,6 @@ impl<'a, Log: LogLevel> Search<'a, Log> {
return score;
}

// don't bother searching if the board is in a draw state
if board.is_draw() {
return Score::DRAW;
}

// get all legal moves
let mut move_list = MoveList::new();
let mut order_list = ArrayVec::<MoveOrder, MAX_MOVE_LIST_SIZE>::new();
Expand Down Expand Up @@ -497,7 +492,11 @@ impl<'a, Log: LogLevel> Search<'a, Log> {

// make the move
board.make_move_unchecked(&mv).unwrap();
let score : Score =
let mut score = Score::DRAW;

// Don't bother searching drawn positions
if !board.is_draw() {
score =
// Principal Variation Search (PVS)
if Node::PV && i == 0 {
-self.negamax::<PvNode>(board, depth - 1, ply + 1, -beta, -alpha_use, &mut local_pv)
Expand All @@ -517,6 +516,7 @@ impl<'a, Log: LogLevel> Search<'a, Log> {
temp_score
}
};
}

// undo the move
board.unmake_move().unwrap();
Expand Down