Fix empty EvalFile option

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index c48b74bcc76ddc0761cdb9c44d961dffa4b0f2c0..a487ed1305b1ccdc8aabe5b42858ec71799b5895 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -801,7 +801,7 @@ namespace {
         assert(eval - beta >= 0);
 
         // Null move dynamic reduction based on depth and value
-        Depth R = (1090 + 81 * depth) / 256 + std::min(int(eval - beta) / 205, 3);
+        Depth R = std::min(int(eval - beta) / 205, 3) + depth / 3 + 4;
 
         ss->currentMove = MOVE_NULL;
         ss->continuationHistory = &thisThread->continuationHistory[0][0][NO_PIECE][0];
@@ -1173,8 +1173,8 @@ moves_loop: // When in check, search starts here
 
           // In general we want to cap the LMR depth search at newDepth. But if
           // reductions are really negative and movecount is low, we allow this move
-          // to be searched deeper than the first move, unless ttMove was extended by 2.
-          Depth d = std::clamp(newDepth - r, 1, newDepth + (r < -1 && moveCount <= 5 && !doubleExtension));
+          // to be searched deeper than the first move in specific cases.
+          Depth d = std::clamp(newDepth - r, 1, newDepth + (r < -1 && (moveCount <= 5 || (depth > 6 && PvNode)) && !doubleExtension));
 
           value = -search<NonPV>(pos, ss+1, -(alpha+1), -alpha, d, true);