Remove rook passers eval completely

Tested in no-regression mode.

Passed STC
LLR: 2.95 (-2.94,2.94) [-3.00,1.00]
Total: 17727 W: 3248 L: 3122 D: 11357

And (a very long!) LTC
LLR: 2.96 (-2.94,2.94) [-3.00,1.00]
Total: 106327 W: 16258 L: 16265 D: 73804

bench: 7396783

diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index a2ed91f8c9e1e8319926e1dbb534ac3ed336f090..ea65ab3862a57627559c97db1f754feb14aac9ed 100644 (file)
--- a/src/evaluate.cpp
+++ b/src/evaluate.cpp
@@ -638,21 +638,6 @@ namespace {
             }
         } // rr != 0
 
-        // Rook pawns are a special case: They are sometimes worse, and
-        // sometimes better than other passed pawns. It is difficult to find
-        // good rules for determining whether they are good or bad. For now,
-        // we try the following: Increase the value for rook pawns if the
-        // other side has no pieces apart from a knight, and decrease the
-        // value if the other side has a rook or queen.
-        if (file_of(s) == FILE_A || file_of(s) == FILE_H)
-        {
-            if (pos.non_pawn_material(Them) <= KnightValueMg)
-                ebonus += ebonus / 4;
-
-            else if (pos.pieces(Them, ROOK, QUEEN))
-                ebonus -= ebonus / 4;
-        }
-
         if (pos.count<PAWN>(Us) < pos.count<PAWN>(Them))
             ebonus += ebonus / 4;