Do not use SEE in evasion scoring

[stockfish] / src / movepick.cpp

diff --git a/src/movepick.cpp b/src/movepick.cpp
index bbe1897e0d72920058ec11ee0a1c1664549d7538..1ec56c2f700a7c2a30bedd371af100fc6a29e9ec 100644 (file)
--- a/src/movepick.cpp
+++ b/src/movepick.cpp
@@ -159,19 +159,13 @@ void MovePicker::score<QUIETS>() {
 
 template<>
 void MovePicker::score<EVASIONS>() {
-  // Try winning and equal captures ordered by MVV/LVA, then non-captures ordered
-  // by history value, then bad captures and quiet moves with a negative SEE ordered
-  // by SEE value.
+  // Try captures ordered by MVV/LVA, then non-captures ordered by history value
   const HistoryStats& history = pos.this_thread()->history;
   const FromToStats& fromTo = pos.this_thread()->fromTo;
   Color c = pos.side_to_move();
-  Value see;
 
   for (auto& m : *this)
-      if ((see = pos.see_sign(m)) < VALUE_ZERO)
-          m.value = see - HistoryStats::Max; // At the bottom
-
-      else if (pos.capture(m))
+      if (pos.capture(m))
           m.value =  PieceValue[MG][pos.piece_on(to_sq(m))]
                    - Value(type_of(pos.moved_piece(m))) + HistoryStats::Max;
       else
@@ -277,7 +271,7 @@ Move MovePicker::next_move() {
   case EVASIONS_INIT:
       cur = moves;
       endMoves = generate<EVASIONS>(pos, cur);
-      if (endMoves - cur > 1)
+      if (endMoves - cur - (ttMove != MOVE_NONE) > 1)
           score<EVASIONS>();
       ++stage;