X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;fp=src%2Fsearch.cpp;h=27c2c84e9dd580d8bbc26622a09cabb2767ef5da;hp=10a36cbf26131b6ac449a92885b18579c6d27aaa;hb=d9ec82e7438716671168d78eee26fae327249e8c;hpb=c53d2ec253557d8a679197becb7ba9a6aa393ecc

diff --git a/src/search.cpp b/src/search.cpp
index 10a36cbf..27c2c84e 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -1468,14 +1468,19 @@ Value qsearch(Position& pos, Stack* ss, Value alpha, Value beta, Depth depth) {
             ss->staticEval = bestValue =
               (ss - 1)->currentMove != MOVE_NULL ? evaluate(pos) : -(ss - 1)->staticEval;
 
-        // Stand pat. Return immediately if static value is at least beta
+        // Stand pat. Return immediately if bestValue is at least beta at non-Pv nodes.
+        // At PvNodes set bestValue between alpha and beta instead
         if (bestValue >= beta)
         {
-            if (!ss->ttHit)
-                tte->save(posKey, value_to_tt(bestValue, ss->ply), false, BOUND_LOWER, DEPTH_NONE,
-                          MOVE_NONE, ss->staticEval);
+            if (!PvNode || abs(bestValue) >= VALUE_TB_WIN_IN_MAX_PLY)
+            {
+                if (!ss->ttHit)
+                    tte->save(posKey, value_to_tt(bestValue, ss->ply), false, BOUND_LOWER,
+                              DEPTH_NONE, MOVE_NONE, ss->staticEval);
 
-            return bestValue;
+                return bestValue;
+            }
+            bestValue = std::min((alpha + beta) / 2, beta - 1);
         }
 
         if (bestValue > alpha)