Showing with 4 additions and 2 deletions.

+4 −2 src/search.cpp
diff --git a/src/search.cpp b/src/search.cpp
@@ -727,8 +727,10 @@ namespace {
         &&  excludedMove == MOVE_NONE
         &&  abs(beta) < VALUE_MATE_IN_MAX_PLY)
     {
-        Value rbeta = beta + 200;
-        Depth rdepth = depth - ONE_PLY - 3 * ONE_PLY;
+        double slope = 0.9 + (static_cast<double>(depth) / 66.0);
+        double stdev = 50.0 + depth * 6;
+        Value rbeta = Value((static_cast<double>(beta) + stdev) / slope);
+        Depth rdepth = depth - 4 * ONE_PLY;
 
         assert(rdepth >= ONE_PLY);
         assert((ss-1)->currentMove != MOVE_NONE);