Mix search stats with evaluation

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index bd5eb2608cfa6714879d2cfd33b0e87ef5bc8a7c..d43a875f68168f4c58f64907daba4c88daf4df7d 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -82,7 +82,7 @@ namespace {
   // History and stats update bonus, based on depth
   int stat_bonus(Depth depth) {
     int d = depth / ONE_PLY;
-    return d > 17 ? 0 : 33 * d * d + 66 * d - 66;
+    return d > 17 ? 0 : 29 * d * d + 138 * d - 134;
   }
 
   // Skill structure is used to implement strength limit
@@ -258,7 +258,7 @@ void MainThread::search() {
 
       // Vote according to score and depth
       for (Thread* th : Threads)
-          votes[th->rootMoves[0].pv[0]] +=  int(th->rootMoves[0].score - minScore)  
+          votes[th->rootMoves[0].pv[0]] +=  int(th->rootMoves[0].score - minScore)
                                           + int(th->completedDepth);
 
       // Select best thread
@@ -584,7 +584,8 @@ namespace {
         if (   Threads.stop.load(std::memory_order_relaxed)
             || pos.is_draw(ss->ply)
             || ss->ply >= MAX_PLY)
-            return (ss->ply >= MAX_PLY && !inCheck) ? evaluate(pos) : VALUE_DRAW;
+            return (ss->ply >= MAX_PLY && !inCheck) ? evaluate(pos) - 10 * ((ss-1)->statScore > 0)
+                                                    : VALUE_DRAW;
 
         // Step 3. Mate distance pruning. Even if we mate at the next move our score
         // would be at best mate_in(ss->ply+1), but if alpha is already bigger because
@@ -712,7 +713,7 @@ namespace {
     {
         // Never assume anything on values stored in TT
         if ((ss->staticEval = eval = tte->eval()) == VALUE_NONE)
-            eval = ss->staticEval = evaluate(pos);
+            eval = ss->staticEval = evaluate(pos) - 10 * ((ss-1)->statScore > 0);
 
         // Can ttValue be used as a better position evaluation?
         if (    ttValue != VALUE_NONE
@@ -722,7 +723,7 @@ namespace {
     else
     {
         ss->staticEval = eval =
-        (ss-1)->currentMove != MOVE_NULL ? evaluate(pos)
+        (ss-1)->currentMove != MOVE_NULL ? evaluate(pos) - 10 * ((ss-1)->statScore > 0)
                                          : -(ss-1)->staticEval + 2 * Eval::Tempo;
 
         tte->save(posKey, VALUE_NONE, BOUND_NONE, DEPTH_NONE, MOVE_NONE,
@@ -747,7 +748,7 @@ namespace {
     // Step 9. Null move search with verification search (~40 Elo)
     if (   !PvNode
         && (ss-1)->currentMove != MOVE_NULL
-        && (ss-1)->statScore < 22500
+        && (ss-1)->statScore < 23200
         &&  eval >= beta
         &&  ss->staticEval >= beta - 36 * depth / ONE_PLY + 225
         && !excludedMove