X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=src%2Fevaluate.cpp;h=f70014e293d2ac9d88d5e3fe9d62f8102ea70e2c;hb=460892382a11cca0fe645390ff96910bf03f6b20;hp=ad420fbdae4917ba01070f5f2b7ae98991e263ed;hpb=4f6b1bf3bee68f138d1b5fc234fd25901cffa42c;p=stockfish

diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index ad420fbd..f70014e2 100644
--- a/src/evaluate.cpp
+++ b/src/evaluate.cpp
@@ -27,7 +27,7 @@
 #include "material.h"
 #include "pawns.h"
 #include "thread.h"
-#include "ucioption.h"
+#include "uci.h"
 
 namespace {
 
@@ -499,9 +499,11 @@ namespace {
 
     assert(target & (pos.pieces(C) ^ pos.pieces(C, KING)));
 
-    PieceType pt;
-    for (pt = QUEEN; !(target & pos.pieces(C, pt)); --pt) {}
-    return pt;
+    for (PieceType pt = QUEEN; pt > PAWN; --pt)
+        if (target & pos.pieces(C, pt))
+            return pt;
+
+    return PAWN;
   }
 
 
@@ -764,27 +766,25 @@ namespace {
     if (    ei.mi->game_phase() < PHASE_MIDGAME
         && (sf == SCALE_FACTOR_NORMAL || sf == SCALE_FACTOR_ONEPAWN))
     {
-        if (pos.opposite_bishops()) {
-            // Ignoring any pawns, do both sides only have a single bishop and no
-            // other pieces?
+        if (pos.opposite_bishops())
+        {
+            // Endgame with opposite-colored bishops and no other pieces (ignoring pawns)
+            // is almost a draw, in case of KBP vs KB is even more a draw.
             if (   pos.non_pawn_material(WHITE) == BishopValueMg
                 && pos.non_pawn_material(BLACK) == BishopValueMg)
-            {
-                // Check for KBP vs KB with only a single pawn that is almost
-                // certainly a draw or at least two pawns.
-                bool one_pawn = (pos.count<PAWN>(WHITE) + pos.count<PAWN>(BLACK) == 1);
-                sf = one_pawn ? ScaleFactor(8) : ScaleFactor(32);
-            }
+                sf = more_than_one(pos.pieces(PAWN)) ? ScaleFactor(32) : ScaleFactor(8);
+
+            // Endgame with opposite-colored bishops, but also other pieces. Still
+            // a bit drawish, but not as drawish as with only the two bishops.
             else
-                // Endgame with opposite-colored bishops, but also other pieces. Still
-                // a bit drawish, but not as drawish as with only the two bishops.
                  sf = ScaleFactor(50 * sf / SCALE_FACTOR_NORMAL);
-        } else if (    abs(eg_value(score)) <= BishopValueEg
-                   &&  ei.pi->pawn_span(strongSide) <= 1
-                   && !pos.pawn_passed(~strongSide, pos.king_square(~strongSide))) {
-            // Endings where weaker side can be place his king in front of the opponent's pawns are drawish.
-            sf = ScaleFactor(ScalePawnSpan[ei.pi->pawn_span(strongSide)]);
         }
+        // Endings where weaker side can place his king in front of the opponent's
+        // pawns are drawish.
+        else if (    abs(eg_value(score)) <= BishopValueEg
+                 &&  ei.pi->pawn_span(strongSide) <= 1
+                 && !pos.pawn_passed(~strongSide, pos.king_square(~strongSide)))
+                 sf = ScaleFactor(ScalePawnSpan[ei.pi->pawn_span(strongSide)]);
     }
 
     // Interpolate between a middlegame and a (scaled by 'sf') endgame score