X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fendgame.cpp;h=681b290c4711edd8d2d08fe92dd3afcc24b67fb0;hp=ee6705aaeaa0a157b70f94a06cfc87642d5b8b96;hb=3e4fed3a91752da394f7c912f4e5e29dc39391f6;hpb=e6310b3469b07b6bbecf8d8f75367a655090f22b

diff --git a/src/endgame.cpp b/src/endgame.cpp
index ee6705aa..681b290c 100644
--- a/src/endgame.cpp
+++ b/src/endgame.cpp
@@ -59,6 +59,9 @@ namespace {
   const int PushClose[8] = { 0, 0, 100, 80, 60, 40, 20, 10 };
   const int PushAway [8] = { 0, 5, 20, 40, 60, 80, 90, 100 };
 
+  // Pawn Rank based scaling factors used in KRPPKRP endgame
+  const int KRPPKRPScaleFactors[RANK_NB] = { 0, 9, 10, 14, 21, 44, 0, 0 };
+
 #ifndef NDEBUG
   bool verify_material(const Position& pos, Color c, Value npm, int pawnsCnt) {
     return pos.non_pawn_material(c) == npm && pos.count<PAWN>(c) == pawnsCnt;
@@ -160,7 +163,7 @@ Value Endgame<KXK>::operator()(const Position& pos) const {
       ||(pos.count<BISHOP>(strongSide) && pos.count<KNIGHT>(strongSide))
       ||(pos.count<BISHOP>(strongSide) > 1 && opposite_colors(pos.squares<BISHOP>(strongSide)[0],
                                                               pos.squares<BISHOP>(strongSide)[1])))
-      result += VALUE_KNOWN_WIN;
+      result = std::min(result + VALUE_KNOWN_WIN, VALUE_MATE_IN_MAX_PLY - 1);
 
   return strongSide == pos.side_to_move() ? result : -result;
 }
@@ -600,14 +603,8 @@ ScaleFactor Endgame<KRPPKRP>::operator()(const Position& pos) const {
       && distance<File>(bksq, wpsq2) <= 1
       && relative_rank(strongSide, bksq) > r)
   {
-      switch (r) {
-      case RANK_2: return ScaleFactor(10);
-      case RANK_3: return ScaleFactor(10);
-      case RANK_4: return ScaleFactor(15);
-      case RANK_5: return ScaleFactor(20);
-      case RANK_6: return ScaleFactor(40);
-      default: assert(false);
-      }
+      assert(r > RANK_1 && r < RANK_7);
+      return ScaleFactor(KRPPKRPScaleFactors[r]);
   }
   return SCALE_FACTOR_NONE;
 }