X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fevaluate.cpp;h=d972db5a1ccc26f178e962542c358a432a383073;hp=67e0592105516cae1d2988d4f1e328a8b1bea161;hb=cca643669db016f20c6e91f50892a0b44f297a48;hpb=eb4a124b8859a6029b61f403e0a9415fa748e4bd

diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index 67e05921..d972db5a 100644
--- a/src/evaluate.cpp
+++ b/src/evaluate.cpp
@@ -128,6 +128,7 @@ namespace {
 
   // Assorted bonuses and penalties
   constexpr Score BishopPawns         = S(  3,  7);
+  constexpr Score BishopXRayPawns     = S(  4,  5);
   constexpr Score CorneredBishop      = S( 50, 50);
   constexpr Score FlankAttacks        = S(  8,  0);
   constexpr Score Hanging             = S( 69, 36);
@@ -318,6 +319,9 @@ namespace {
                 score -= BishopPawns * pos.pawns_on_same_color_squares(Us, s)
                                      * (!(attackedBy[Us][PAWN] & s) + popcount(blocked & CenterFiles));
 
+                // Penalty for all enemy pawns x-rayed
+                score -= BishopXRayPawns * popcount(PseudoAttacks[BISHOP][s] & pos.pieces(Them, PAWN));
+
                 // Bonus for bishop on a long diagonal which can "see" both center squares
                 if (more_than_one(attacks_bb<BISHOP>(s, pos.pieces(PAWN)) & Center))
                     score += LongDiagonalBishop;
@@ -735,6 +739,7 @@ namespace {
                     + 24 * infiltration
                     + 51 * !pos.non_pawn_material()
                     - 43 * almostUnwinnable
+                    -  2 * pos.rule50_count()
                     -110 ;
 
     Value mg = mg_value(score);
@@ -774,8 +779,6 @@ namespace {
         }
         else
             sf = std::min(sf, 36 + 7 * pos.count<PAWN>(strongSide));
-
-        sf = std::max(0, sf - (pos.rule50_count() - 12) / 4);
     }
 
     return ScaleFactor(sf);
@@ -852,7 +855,8 @@ namespace {
         Trace::add(TOTAL, score);
     }
 
-    return  (pos.side_to_move() == WHITE ? v : -v) + Tempo; // Side to move point of view
+    // Side to move point of view
+    return (pos.side_to_move() == WHITE ? v : -v) + Tempo;
   }
 
 } // namespace