From 0a8207c5bba7eac72a459e18be5cbd8df35b1704 Mon Sep 17 00:00:00 2001
From: H.G. Muller <h.g.muller@hccnet.nl>
Date: Sat, 16 Feb 2013 18:05:46 +0100
Subject: [PATCH] Fix check extension
Check extension in micro-Max was not be awarded when a piece other than King
captured the checker. In the code this was still tested assuming the piece
number of the King would always be 3, while in Fairy-Max every piece can be
Royal, based on the sign of its piece value w[]. In many game definitions
piece 3 was actually not a King at all.
---
changelog | 1 +
fairymax.c | 2 +-
2 files changed, 2 insertions(+), 1 deletions(-)
diff --git a/changelog b/changelog
index e8a3654..06089ba 100644
--- a/changelog
+++ b/changelog
@@ -110,6 +110,7 @@
* Spurious result claims after under-promotion
* False mate claims in Spartan when promotion to K was possible
* Fix bug in Berolina e.p. capture that is actually non-capture
+ * Fix conditions for check extension on capture of checker
* Fix Clear Hash option, which did not work at all
* Fix addition of 6th & 7th-rank Pawn bonus when setting up position
* Adapt score by true piece value in case of (under-)promotion
diff --git a/fairymax.c b/fairymax.c
index 6f420ae..769da7f 100644
--- a/fairymax.c
+++ b/fairymax.c
@@ -218,7 +218,7 @@ int k,q,l,e,E,z,n; /* (q,l)=window, e=current eval. score, E=e.p. sqr.*/
v+=e+i;V=m>q?m:q; /*** new eval & alpha ****/
if(z&S)V=m-margin>q?m-margin:q; /* multiPV */
C=d-1-(d>5&p>2&!t&!h); /* nw depth, reduce non-cpt.*/
- C=R<EG|P-I|d<3||t&&p-3?C:d; /* extend 1 ply if in-check */
+ C=R<EG|P-I|d<3||t&&w[p]>0?C:d; /* extend 1 ply if in-check */
do
s=C>2|v>V?-D(16-k,-l,-V,-v,/*** futility, recursive eval. of reply */
F,y&255,C):v;
--
1.7.0.4