From: Gary Linscott <glinscott@gmail.com>
Date: Sat, 26 Jan 2013 20:35:00 +0000 (-0500)
Subject: Bring back just bishop pins
X-Git-Url: https://git.sesse.net/?p=stockfish;a=commitdiff_plain;h=57797822f81386fc277de73599a05ad06a7dc7b6

Bring back just bishop pins
---

diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index 984a85a6..e29b9b0f 100644
--- a/src/evaluate.cpp
+++ b/src/evaluate.cpp
@@ -577,6 +577,12 @@ Value do_evaluate(const Position& pos, Value& margin) {
 
         mobility += MobilityBonus[Piece][mob];
 
+        if (Piece == BISHOP && (PseudoAttacks[Piece][pos.king_square(Them)] & s)) {
+             const Bitboard between = BetweenBB[s][pos.king_square(Them)] & pos.pieces();
+             if (!more_than_one(between))
+                 score += make_score(25, 25);
+        }
+
         // Decrease score if we are attacked by an enemy pawn. Remaining part
         // of threat evaluation must be done later when we have full attack info.
         if (ei.attackedBy[Them][PAWN] & s)