X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=72ab9a1228d36bc58deb8d40e0c92c45fb896f87;hp=9c1d0b5eca66e1e928accfaec998d3f3d426d2d1;hb=7d2530873e6eb2b46ca2ffb548f9b993bbe1de41;hpb=18505f1fc40643ed033f681c36dc5efa3ddf2a05

diff --git a/src/search.cpp b/src/search.cpp
index 9c1d0b5e..72ab9a12 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -708,16 +708,16 @@ namespace {
         ss->currentMove = MOVE_NULL;
 
         // Null move dynamic reduction based on depth
-        int R = 3 + (depth >= 5 * ONE_PLY ? depth / 8 : 0);
+        Depth R = 3 * ONE_PLY + depth / 4;
 
         // Null move dynamic reduction based on value
         if (refinedValue - PawnValueMidgame > beta)
-            R++;
+            R += ONE_PLY;
 
         pos.do_null_move<true>(st);
         (ss+1)->skipNullMove = true;
-        nullValue = depth-R*ONE_PLY < ONE_PLY ? -qsearch<NonPV>(pos, ss+1, -beta, -alpha, DEPTH_ZERO)
-                                              : - search<NonPV>(pos, ss+1, -beta, -alpha, depth-R*ONE_PLY);
+        nullValue = depth-R < ONE_PLY ? -qsearch<NonPV>(pos, ss+1, -beta, -alpha, DEPTH_ZERO)
+                                      : - search<NonPV>(pos, ss+1, -beta, -alpha, depth-R);
         (ss+1)->skipNullMove = false;
         pos.do_null_move<false>(st);
 
@@ -732,7 +732,7 @@ namespace {
 
             // Do verification search at high depths
             ss->skipNullMove = true;
-            Value v = search<NonPV>(pos, ss, alpha, beta, depth-R*ONE_PLY);
+            Value v = search<NonPV>(pos, ss, alpha, beta, depth-R);
             ss->skipNullMove = false;
 
             if (v >= beta)