Skip LMR for 2nd move at the root only

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index 0a12c85b721a484363c6a6ce7988ac834543bc9b..409a3c1d429aa666c7b67169a10ebb871653fe77 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -1171,7 +1171,7 @@ moves_loop:  // When in check, search starts here
         // We use various heuristics for the sons of a node after the first son has
         // been searched. In general, we would like to reduce them, but there are many
         // cases where we extend a son if it has good chances to be "interesting".
-        if (depth >= 2 && moveCount > 1 + (PvNode && ss->ply <= 1)
+        if (depth >= 2 && moveCount > 1 + rootNode
             && (!ss->ttPv || !capture || (cutNode && (ss - 1)->moveCount > 1)))
         {
             // In general we want to cap the LMR depth search at newDepth, but when
@@ -1687,7 +1687,7 @@ void update_all_stats(const Position& pos,
     PieceType              captured;
 
     int quietMoveBonus = stat_bonus(depth + 1);
-    int quietMoveMalus = stat_malus(depth + 1);
+    int quietMoveMalus = stat_malus(depth);
 
     if (!pos.capture_stage(bestMove))
     {
@@ -1898,9 +1898,9 @@ string UCI::pv(const Position& pos, Depth depth) {
 }
 
 
-// Called in case we have no ponder move
-// before exiting the search, for instance, in case we stop the search during a
-// fail high at root. We try hard to have a ponder move to return to the GUI,
+// Called in case we have no ponder move before exiting the search,
+// for instance, in case we stop the search during a fail high at root.
+// We try hard to have a ponder move to return to the GUI,
 // otherwise in case of 'ponder on' we have nothing to think about.
 bool RootMove::extract_ponder_from_tt(Position& pos) {