Try razoring only for depth > OnePly

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index a4ce7eff3abf10c7a76c057c75271a4f1a4949df..54ff467c1e563314ffed6804744fb1226ee555cf 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -1239,10 +1239,13 @@ namespace {
     // Null move search not allowed, try razoring
     else if (   !value_is_mate(beta)
              && approximateEval < beta - RazorMargin
-             && depth < RazorDepth)
+             && depth < RazorDepth
+             && depth > OnePly
+             && ttMove == MOVE_NONE
+             && !pos.has_pawn_on_7th(pos.side_to_move()))
     {
         Value v = qsearch(pos, ss, beta-1, beta, Depth(0), ply, threadID);
-        if (v < beta - RazorMargin / 2)
+        if (v < beta - RazorMargin / 2 - int(depth - OnePly) * RazorMargin / 8)
             return v;
     }
 
@@ -1314,12 +1317,14 @@ namespace {
               continue;
 
           // Value based pruning
-          if (depth < 6 * OnePly && approximateEval < beta)
+          if (depth < 7 * OnePly && approximateEval < beta)
           {
               if (futilityValue == VALUE_NONE)
                   futilityValue =  evaluate(pos, ei, threadID)
-                                + (depth < 2 * OnePly ? FutilityMargin1
-                                                      : FutilityMargin2 + (depth - 2*OnePly) * 32);
+                                + (depth < 2 * OnePly ? FutilityMargin1 :
+                                + (depth < 6 * OnePly ? FutilityMargin2 + (depth - 2*OnePly) * 32
+                                                      : FutilityMargin2 + (depth - 2*OnePly) * 64));
+
               if (futilityValue < beta)
               {
                   if (futilityValue > bestValue)