Reintroduce king infiltration

[stockfish] / src / evaluate.cpp

diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index 17597648bf36393fa2067ccbaf2ee071c33e51d2..df7ff5ea33776e61eb7fb75fa9365d58bc4c1128 100644 (file)
--- a/src/evaluate.cpp
+++ b/src/evaluate.cpp
@@ -708,14 +708,18 @@ namespace {
                            &&  outflanking < 0
                            && !pawnsOnBothFlanks;
 
+    bool infiltration = rank_of(pos.square<KING>(WHITE)) > RANK_4
+                     || rank_of(pos.square<KING>(BLACK)) < RANK_5;
+
     // Compute the initiative bonus for the attacking side
     int complexity =   9 * pe->passed_count()
                     + 11 * pos.count<PAWN>()
                     +  9 * outflanking
                     + 21 * pawnsOnBothFlanks
+                    + 24 * infiltration
                     + 51 * !pos.non_pawn_material()
                     - 43 * almostUnwinnable
-                    - 95 ;
+                    -110 ;
 
     // Give more importance to non-material score
     Value mg = mg_value(score);