Do not razor after a null move

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index 3ad5423d9d41a7f4600dc97cce32bed306514b2c..3838375fa5517029f5c9d6e1b38018d83a490249 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -1309,6 +1309,7 @@ namespace {
     else if (   !value_is_mate(beta)
              && depth < RazorDepth
              && approximateEval < beta - RazorApprMargins[int(depth) - 2]
+             && ss[ply - 1].currentMove != MOVE_NULL
              && ttMove == MOVE_NONE
              && !pos.has_pawn_on_7th(pos.side_to_move()))
     {
@@ -1921,7 +1922,7 @@ namespace {
   // Constructor
 
   RootMove::RootMove() {
-    nodes = cumulativeNodes = 0ULL;
+    nodes = cumulativeNodes = ourBeta = theirBeta = 0ULL;
   }
 
   // RootMove::operator<() is the comparison function used when
@@ -1957,22 +1958,20 @@ namespace {
         for (int k = 0; !includeMove && searchMoves[k] != MOVE_NONE; k++)
             includeMove = (searchMoves[k] == mlist[i].move);
 
-        if (includeMove)
-        {
-            // Find a quick score for the move
-            StateInfo st;
-            SearchStack ss[PLY_MAX_PLUS_2];
-
-            moves[count].move = mlist[i].move;
-            moves[count].nodes = 0ULL;
-            pos.do_move(moves[count].move, st);
-            moves[count].score = -qsearch(pos, ss, -VALUE_INFINITE, VALUE_INFINITE,
-                                          Depth(0), 1, 0);
-            pos.undo_move(moves[count].move);
-            moves[count].pv[0] = moves[i].move;
-            moves[count].pv[1] = MOVE_NONE; // FIXME
-            count++;
-        }
+        if (!includeMove)
+            continue;
+
+        // Find a quick score for the move
+        StateInfo st;
+        SearchStack ss[PLY_MAX_PLUS_2];
+
+        moves[count].move = mlist[i].move;
+        pos.do_move(moves[count].move, st);
+        moves[count].score = -qsearch(pos, ss, -VALUE_INFINITE, VALUE_INFINITE, Depth(0), 1, 0);
+        pos.undo_move(moves[count].move);
+        moves[count].pv[0] = moves[count].move;
+        moves[count].pv[1] = MOVE_NONE; // FIXME
+        count++;
     }
     sort();
   }