Remove Condition For Passed Pawns

miguel-l · snicolet · commit f1088c98228f · 2018-08-10T06:16:29.000+02:00
Currently, we do not consider pawns passed if there is another pawn of the same color in front of them. It appears that this condition is not necessary. The idea is that the doubled pawns are likely to be weak and one of them will be likely captured anyway. On the other hand, if we do somehow manage to promote a pawn, then the pawn behind it becomes passed as well. In any case, the end result is we end up with an extra potentially passed pawn. The current evaluation for passed pawns already handles this case by also scaling down this effect. STC: LLR: 2.96 (-2.94,2.94) [-3.00,1.00] Total: 28291 W: 6287 L: 6178 D: 15826 http://tests.stockfishchess.org/tests/view/5b6c4b960ebc5902bdb9f256 LTC: LLR: 2.96 (-2.94,2.94) [-3.00,1.00] Total: 30717 W: 5256 L: 5151 D: 20310 http://tests.stockfishchess.org/tests/view/5b6c82980ebc5902bdb9f863 Bench: 4938285
diff --git a/src/pawns.cpp b/src/pawns.cpp
@@ -118,7 +118,6 @@ namespace {
         // which could become passed after one or two pawn pushes when are
         // not attacked more times than defended.
         if (   !(stoppers ^ lever ^ leverPush)
-            && !(ourPawns & forward_file_bb(Us, s))
             && popcount(supported) >= popcount(lever) - 1
             && popcount(phalanx)   >= popcount(leverPush))
             e->passedPawns[Us] |= s;
