Tweak return value in futility pruning

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index 409a3c1d429aa666c7b67169a10ebb871653fe77..ba5ea2e54f9e3d7f92553016dfd503b11fa2cf12 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -780,7 +780,7 @@ Value search(Position& pos, Stack* ss, Value alpha, Value beta, Depth depth, boo
              >= beta
         && eval >= beta && eval < 29462  // smaller than TB wins
         && (!ttMove || ttCapture))
-        return eval;
+        return (eval + beta) / 2;
 
     // Step 9. Null move search with verification search (~35 Elo)
     if (!PvNode && (ss - 1)->currentMove != MOVE_NULL && (ss - 1)->statScore < 17257 && eval >= beta
@@ -1487,7 +1487,7 @@ Value qsearch(Position& pos, Stack* ss, Value alpha, Value beta, Depth depth) {
     // will be generated.
     Square     prevSq = is_ok((ss - 1)->currentMove) ? to_sq((ss - 1)->currentMove) : SQ_NONE;
     MovePicker mp(pos, ttMove, depth, &thisThread->mainHistory, &thisThread->captureHistory,
-                  contHist, &thisThread->pawnHistory, prevSq);
+                  contHist, &thisThread->pawnHistory);
 
     int quietCheckEvasions = 0;