PV refutation penalty

Extra penalty for PV move in previous ply when it gets refuted.

STC:
LLR: 4.49 (-2.94,2.94) [-1.50,4.50]
Total: 41094 W: 7889 L: 7620 D: 25585

LTC:
LLR: 2.95 (-2.94,2.94) [0.00,6.00]
Total: 12304 W: 1967 L: 1811 D: 8526

Bench: 8373608

Resolves #386

diff --git a/src/search.cpp b/src/search.cpp
index 9689668956e8ae77f147ef1f9203c9a58ffa7e57..3ac52f8c0f9cbd0910b00ab1a05532c198c291b1 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -553,7 +553,7 @@ namespace {
         goto moves_loop;
     }
 
         goto moves_loop;
     }
 

-    moveCount = quietCount = 0;
+    moveCount = quietCount =  ss->moveCount = 0;

     bestValue = -VALUE_INFINITE;
     ss->ply = (ss-1)->ply + 1;
 
     bestValue = -VALUE_INFINITE;
     ss->ply = (ss-1)->ply + 1;
 


@@ -826,6 +826,8 @@ moves_loop: // When in check and at SpNode search starts from here
       }
       else
           ++moveCount;
       }
       else
           ++moveCount;

+      
+      ss->moveCount = moveCount;

 
       if (RootNode)
       {
 
       if (RootNode)
       {


@@ -934,6 +936,7 @@ moves_loop: // When in check and at SpNode search starts from here
       if (!RootNode && !SpNode && !pos.legal(move, ci.pinned))
       {
           moveCount--;
       if (!RootNode && !SpNode && !pos.legal(move, ci.pinned))
       {
           moveCount--;

+          ss->moveCount = moveCount;

           continue;
       }
 
           continue;
       }
 


@@ -1425,8 +1428,8 @@ moves_loop: // When in check and at SpNode search starts from here
             cmh.update(pos.moved_piece(quiets[i]), to_sq(quiets[i]), -bonus);
     }
 
             cmh.update(pos.moved_piece(quiets[i]), to_sq(quiets[i]), -bonus);
     }
 

-    // Extra penalty for TT move in previous ply when it gets refuted
-    if (is_ok((ss-2)->currentMove) && (ss-1)->currentMove == (ss-1)->ttMove && !pos.captured_piece_type())
+    // Extra penalty for PV move in previous ply when it gets refuted
+    if (is_ok((ss-2)->currentMove) && (ss-1)->moveCount==1 && !pos.captured_piece_type())

     {
         Square prevPrevSq = to_sq((ss-2)->currentMove);
         HistoryStats& ttMoveCmh = CounterMovesHistory[pos.piece_on(prevPrevSq)][prevPrevSq];
     {
         Square prevPrevSq = to_sq((ss-2)->currentMove);
         HistoryStats& ttMoveCmh = CounterMovesHistory[pos.piece_on(prevPrevSq)][prevPrevSq];

diff --git a/src/search.h b/src/search.h
index 4e1d3c351ea51db7e887faff24d4c337e06c1919..5ba95fe098a5fef94ae7b7418da376fd82d0f619 100644 (file)
--- a/src/search.h
+++ b/src/search.h
@@ -47,6 +47,7 @@ struct Stack {
   Depth reduction;
   Value staticEval;
   bool skipEarlyPruning;
   Depth reduction;
   Value staticEval;
   bool skipEarlyPruning;

+  int moveCount;

 };
 
 /// RootMove struct is used for moves at the root of the tree. For each root move
 };
 
 /// RootMove struct is used for moves at the root of the tree. For each root move