Adjust reduction less at medium depths

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index 3c2ae3e52df8b0c43f8cc05a132c2adb801bef81..422d4b43a8268b702dd02943bb434c78e0d99262 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -775,8 +775,7 @@ namespace {
     // Step 7. Razoring.
     // If eval is really low check with qsearch if it can exceed alpha, if it can't,
     // return a fail low.
-    if (   depth <= 7
-        && eval < alpha - 369 - 254 * depth * depth)
+    if (eval < alpha - 369 - 254 * depth * depth)
     {
         value = qsearch<NonPV>(pos, ss, alpha - 1, alpha);
         if (value < alpha)
@@ -1178,7 +1177,7 @@ moves_loop: // When in check, search starts here
                          - 4433;
 
           // Decrease/increase reduction for moves with a good/bad history (~30 Elo)
-          r -= ss->statScore / 13628;
+          r -= ss->statScore / (13628 + 4000 * (depth > 7 && depth < 19));
 
           // In general we want to cap the LMR depth search at newDepth, but when
           // reduction is negative, we allow this move a limited search extension