Tuned history reduction

[stockfish] / src / endgame.cpp

diff --git a/src/endgame.cpp b/src/endgame.cpp
index 56583c58890ffb6f7aac25979987719388407477..1a5959e5fea8e4120844d5ac8c868c16c4626a5f 100644 (file)
--- a/src/endgame.cpp
+++ b/src/endgame.cpp
@@ -80,7 +80,6 @@ namespace Endgames {
     add<KNNKP>("KNNKP");
 
     add<KNPK>("KNPK");
-    add<KNPKB>("KNPKB");
     add<KRPKR>("KRPKR");
     add<KRPKB>("KRPKB");
     add<KBPKB>("KBPKB");
@@ -733,27 +732,6 @@ ScaleFactor Endgame<KNPK>::operator()(const Position& pos) const {
 }
 
 
-/// KNP vs KB. If knight can block bishop from taking pawn, it's a win.
-/// Otherwise the position is drawn.
-template<>
-ScaleFactor Endgame<KNPKB>::operator()(const Position& pos) const {
-
-  assert(verify_material(pos, strongSide, KnightValueMg, 1));
-  assert(verify_material(pos, weakSide, BishopValueMg, 0));
-
-  Square pawnSq = pos.square<PAWN>(strongSide);
-  Square bishopSq = pos.square<BISHOP>(weakSide);
-  Square weakKingSq = pos.square<KING>(weakSide);
-
-  // King needs to get close to promoting pawn to prevent knight from blocking.
-  // Rules for this are very tricky, so just approximate.
-  if (forward_file_bb(strongSide, pawnSq) & pos.attacks_from<BISHOP>(bishopSq))
-      return ScaleFactor(distance(weakKingSq, pawnSq));
-
-  return SCALE_FACTOR_NONE;
-}
-
-
 /// KP vs KP. This is done by removing the weakest side's pawn and probing the
 /// KP vs K bitbase: If the weakest side has a draw without the pawn, it probably
 /// has at least a draw with the pawn as well. The exception is when the stronger