feat: redo search if out of aspiration window

1 files changed, 10 insertions, 4 deletions

diff --git a/src/main.c b/src/main.c
index 1c5664a..ddc5a39 100644
--- a/src/main.c
+++ b/src/main.c
@@ -640,6 +640,7 @@ Move iterative_deepening(int* board, int color, long hash, Transposition* transp
   clock_t deadline = start + MOVE_TIME * CLOCKS_PER_SEC;
   int alpha = -INFINITY;
   int beta = +INFINITY;
+  int window_size = 4;
 
   while (depth <= MAX_DEPTH) {
     best_move = move;
@@ -658,10 +659,15 @@ Move iterative_deepening(int* board, int color, long hash, Transposition* transp
     index_to_notation(move.destination, move_in_notation + 2);
     printf("Done (%s with evaluation %.2f)    [%i positions analyzed]\n", move_in_notation, (double)move.value / 10, metrics);
 
-    alpha = move.value - 3;
-    beta = move.value + 3;
-
-    depth++;
+    if (move.value < alpha || move.value > beta) {
+      printf("Out of aspiration window, re-doing the full search\n");
+      alpha = -INFINITY;
+      beta = +INFINITY;
+    } else {
+      alpha = move.value - window_size;
+      beta = move.value + window_size;
+      depth++;
+    }
   }
 
   printf("Max depth (%i) reached in %.2f seconds\n", MAX_DEPTH, (double)(clock() - start) / CLOCKS_PER_SEC);