X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=src%2Fsearch.cpp;h=e9afc1c58b2655374c056161e08f325a1c67d7b7;hb=59d10374ca647feebf9323b21031e47012572fb6;hp=394f228fb4f59956914ab3d014b199934d245716;hpb=ad2a0e356e395038a08324f9ff0afee7fc98b8e9;p=stockfish

diff --git a/src/search.cpp b/src/search.cpp
index 394f228f..e9afc1c5 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -325,7 +325,7 @@ void Thread::search() {
 
       // Age out PV variability metric
       if (mainThread)
-          mainThread->bestMoveChanges *= 0.505, mainThread->failedLow = false;
+          mainThread->bestMoveChanges *= 0.517, mainThread->failedLow = false;
 
       // Save the last iteration's scores before first PV line is searched and
       // all the move scores except the (new) PV are set to -VALUE_INFINITE.
@@ -444,21 +444,21 @@ void Thread::search() {
               const int F[] = { mainThread->failedLow,
                                 bestValue - mainThread->previousScore };
 
-              int improvingFactor = std::max(229, std::min(715, 357 + 119 * F[0] - 6 * F[1]));
+              int improvingFactor = std::max(246, std::min(832, 306 + 119 * F[0] - 6 * F[1]));
 
               // If the bestMove is stable over several iterations, reduce time accordingly
               timeReduction = 1.0;
               for (int i : {3, 4, 5})
                   if (lastBestMoveDepth * i < completedDepth)
-                     timeReduction *= 1.3;
+                     timeReduction *= 1.25;
 
               // Use part of the gained time from a previous stable move for the current move
               double unstablePvFactor = 1.0 + mainThread->bestMoveChanges;
-              unstablePvFactor *= std::pow(mainThread->previousTimeReduction, 0.51) / timeReduction;
+              unstablePvFactor *= std::pow(mainThread->previousTimeReduction, 0.528) / timeReduction;
 
               // Stop the search if we have only one legal move, or if available time elapsed
               if (   rootMoves.size() == 1
-                  || Time.elapsed() > Time.optimum() * unstablePvFactor * improvingFactor / 605)
+                  || Time.elapsed() > Time.optimum() * unstablePvFactor * improvingFactor / 581)
               {
                   // If we are allowed to ponder do not stop the search now but
                   // keep pondering until the GUI sends "ponderhit" or "stop".
@@ -514,7 +514,6 @@ namespace {
     Thread* thisThread = pos.this_thread();
     inCheck = pos.checkers();
     moveCount = captureCount = quietCount = ss->moveCount = 0;
-    ss->statScore = 0;
     bestValue = -VALUE_INFINITE;
     maxValue = VALUE_INFINITE;
 
@@ -554,6 +553,13 @@ namespace {
     (ss+2)->killers[0] = (ss+2)->killers[1] = MOVE_NONE;
     Square prevSq = to_sq((ss-1)->currentMove);
 
+    // Initialize statScore to zero for the grandchildren of the current position.
+    // So statScore is shared between all grandchildren and only the first grandchild
+    // starts with statScore = 0. Later grandchildren start with the last calculated
+    // statScore of the previous grandchild. This influences the reduction rules in
+    // LMR which are based on the statScore of parent position.
+    (ss+2)->statScore = 0;
+
     // Step 4. Transposition table lookup. We don't want the score of a partial
     // search to overwrite a previous full search TT value, so we use a different
     // position key in case of an excluded move.