From: Jörg Oster <osterj165@googlemail.com>
Date: Fri, 18 Oct 2013 08:23:28 +0000 (+0200)
Subject: Score chain pawn also by rank
X-Git-Url: https://git.sesse.net/?p=stockfish;a=commitdiff_plain;h=25cb851f8aa914634666789473a7809695dec6d1;ds=sidebyside

Score chain pawn also by rank

Use the (rescaled) CandidatePassed[] table
that is already rank based.

Passed both short TC
LLR: 2.95 (-2.94,2.94) [-1.50,4.50]
Total: 11048 W: 2272 L: 2135 D: 6641

And long TC
LLR: 2.97 (-2.94,2.94) [0.00,6.00]
Total: 4116 W: 769 L: 645 D: 2702

bench: 8440524
---

diff --git a/src/pawns.cpp b/src/pawns.cpp
index 37db2cf5..1934628e 100644
--- a/src/pawns.cpp
+++ b/src/pawns.cpp
@@ -176,7 +176,7 @@ namespace {
             value -= Backward[opposed][f];
 
         if (chain)
-            value += ChainMember[f];
+            value += ChainMember[f] + CandidatePassed[relative_rank(Us, s)] / 2;
 
         if (candidate)
         {