feat: also check 3-fold repetition in quiesence

1 files changed, 10 insertions, 5 deletions

diff --git a/src/grossmeister/search.rs b/src/grossmeister/search.rs
index 43423e4..532e9ed 100644
--- a/src/grossmeister/search.rs
+++ b/src/grossmeister/search.rs
@@ -22,6 +22,11 @@ impl Grossmeister {
         let mut killer_moves = Vec::new();
         let color = self.board.color();
 
+        if self.board.positions.iter().filter(|p| **p == self.board.hash).count() >= 3 {
+            // Draw by repetition
+            return (0.0, principal_variation);
+        }
+
         if let Some(transposition) = self.transposition() {
             if transposition.depth == depth_left {
                 match transposition.node_type {
@@ -45,11 +50,6 @@ impl Grossmeister {
             }
         }
 
-        if self.board.positions.iter().filter(|p| **p == self.board.hash).count() >= 3 {
-            // Draw by repetition
-            return (0.0, principal_variation);
-        }
-
         if depth_left == 0 {
             return (self.quiscence(alpha, beta), principal_variation);
         }
@@ -154,6 +154,11 @@ impl Grossmeister {
         let mut moves = self.board.generate_pseudolegal_moves();
         moves = self.order_moves(moves, Vec::new());
 
+        if self.board.positions.iter().filter(|p| **p == self.board.hash).count() >= 3 {
+            // Draw by repetition
+            return 0.0;
+        }
+
         if !self.board.is_king_in_check(color) {
             // If we are not in check, we can evaluate stand pat
             let stand_pat = self.evaluate();