Changed a option name more descriptive, "Training" -> "PruneAtShallowDepthOnPvNode". The default value was changed but the default behavior is not changed.

Changed to set a global option prune_at_shallow_depth_on_pv_node on a callback function.

src/search.cpp

@@ -54,6 +54,10 @@ using std::string;
 using Eval::evaluate;
 using namespace Search;
 
+#if defined(EVAL_LEARN)
+bool Search::prune_at_shallow_depth_on_pv_node = false;
+#endif
+
 namespace {
 
   // Different node types, used as a template parameter
@@ -68,8 +72,6 @@ namespace {
     return Value(223 * (d - improving));
   }
 
-  bool training;
-
   // Reductions lookup table, initialized at startup
   int Reductions[MAX_MOVES]; // [depth or moveNumber]
 
@@ -195,8 +197,6 @@ void Search::init() {
 
   for (int i = 1; i < MAX_MOVES; ++i)
       Reductions[i] = int((22.0 + std::log(Threads.size())) * std::log(i));
-
-  training = Options["Training"];
 }
 
 
@@ -1011,7 +1011,9 @@ moves_loop: // When in check, search starts from here
 
       // Step 12. Pruning at shallow depth (~200 Elo)
       if (  !rootNode
-          && !(training && PvNode)
+#ifdef EVAL_LEARN
+          && !(!prune_at_shallow_depth_on_pv_node && PvNode)
+#endif
           && pos.non_pawn_material(us)
           && bestValue > VALUE_TB_LOSS_IN_MAX_PLY)
       {