Further increase SEE prune depth

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index 7970a393d003848a537f9e4c18650266fd12580d..7a06dad93f94035b046c9384938ce6d8d0b983b1 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -293,7 +293,6 @@ namespace {
     Stack ss[MAX_PLY_PLUS_2];
     int depth, prevBestMoveChanges;
     Value bestValue, alpha, beta, delta;
-    bool triedEasyMove = false;
 
     memset(ss, 0, 4 * sizeof(Stack));
     depth = BestMoveChanges = 0;
@@ -440,12 +439,10 @@ namespace {
             // Stop search early if one move seems to be much better than others
             if (    depth >= 12
                 && !stop
-                && !triedEasyMove
                 &&  PVSize == 1
                 && (   RootMoves.size() == 1
                     || Time::now() - SearchTime > (TimeMgr.available_time() * 20) / 100))
             {
-                triedEasyMove = true;
                 Value rBeta = bestValue - 2 * PawnValueMg;
                 (ss+1)->excludedMove = RootMoves[0].pv[0];
                 (ss+1)->skipNullMove = true;
@@ -888,7 +885,7 @@ split_point_start: // At split points actual search starts from here
           }
 
           // Prune moves with negative SEE at low depths
-          if (   predictedDepth < 3 * ONE_PLY
+          if (   predictedDepth < 4 * ONE_PLY
               && pos.see_sign(move) < 0)
           {
               if (SpNode)