From 57797822f81386fc277de73599a05ad06a7dc7b6 Mon Sep 17 00:00:00 2001
From: Gary Linscott <glinscott@gmail.com>
Date: Sat, 26 Jan 2013 15:35:00 -0500
Subject: [PATCH] Bring back just bishop pins

---
 src/evaluate.cpp | 6 ++++++
 1 file changed, 6 insertions(+)

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)
-- 
2.39.2