<s>
Crafty	B-Application
is	O
a	O
chess	B-Application
program	I-Application
written	O
by	O
UAB	O
professor	O
Dr.	O
Robert	O
Hyatt	O
,	O
with	O
continual	O
development	O
and	O
assistance	O
from	O
Michael	O
Byrne	O
,	O
Tracy	O
Riegle	O
,	O
and	O
Peter	O
Skinner	O
.	O
</s>
<s>
It	O
is	O
directly	O
derived	O
from	O
Cray	B-General_Concept
Blitz	I-General_Concept
,	O
winner	O
of	O
the	O
1983	O
and	O
1986	O
World	O
Computer	O
Chess	O
Championships	O
.	O
</s>
<s>
Tord	O
Romstad	O
,	O
the	O
author	O
of	O
Stockfish	B-Application
,	O
described	O
Crafty	B-Application
as	O
"	O
arguably	O
the	O
most	O
important	O
and	O
influential	O
chess	B-Application
program	I-Application
ever	O
"	O
.	O
</s>
<s>
Crafty	B-Application
finished	O
in	O
second	O
place	O
in	O
the	O
2010	O
Fifth	O
Annual	O
ACCA	O
Americas	O
 '	O
Computer	O
Chess	O
Championships	O
.	O
</s>
<s>
Crafty	B-Application
lost	O
only	O
one	O
game	O
,	O
namely	O
to	O
the	O
first-place	O
winner	O
,	O
Thinker	O
.	O
</s>
<s>
Crafty	B-Application
also	O
finished	O
in	O
second	O
place	O
in	O
the	O
2010	O
World	O
Computer	O
Rapid	O
Chess	O
Championships	O
.	O
</s>
<s>
Crafty	B-Application
won	O
seven	O
out	O
of	O
nine	O
games	O
,	O
finishing	O
just	O
behind	O
the	O
first-place	O
winner	O
Rybka	O
by	O
only	O
½	O
point	O
.	O
</s>
<s>
In	O
the	O
World	O
Computer	O
Chess	O
Championships	O
2004	O
,	O
running	O
on	O
slightly	O
faster	O
hardware	O
than	O
all	O
other	O
programs	O
,	O
Crafty	B-Application
took	O
fourth	O
place	O
with	O
the	O
same	O
number	O
of	O
points	O
as	O
the	O
third-place	O
finisher	O
,	O
Fritz	B-Application
8	I-Application
.	O
</s>
<s>
On	O
the	O
November	O
2007	O
SSDF	O
ratings	O
list	O
,	O
Crafty	B-Application
was	O
34th	O
with	O
an	O
estimated	O
Elo	O
rating	O
of	O
2608	O
.	O
</s>
<s>
Crafty	B-Application
uses	O
the	O
Chess	B-Application
Engine	I-Application
Communication	O
Protocol	O
and	O
can	O
run	O
under	O
the	O
popular	O
chess	O
interfaces	O
XBoard	B-Application
and	O
Winboard	B-Application
.	O
</s>
<s>
Crafty	B-Application
is	O
written	O
in	O
ANSI	O
C	O
with	O
assembly	O
language	O
routines	O
available	O
on	O
some	O
CPUs	O
,	O
and	O
is	O
very	O
portable	O
.	O
</s>
<s>
Crafty	B-Application
pioneered	O
the	O
use	O
of	O
rotated	O
bitboard	B-Application
data	O
structures	O
to	O
represent	O
the	O
chess	O
board	O
,	O
and	O
was	O
one	O
of	O
the	O
first	O
chess	B-Application
programs	I-Application
to	O
support	O
multiple	O
processors	O
.	O
</s>
<s>
It	O
also	O
includes	O
negascout	B-General_Concept
search	O
,	O
the	O
killer	B-Algorithm
move	I-Algorithm
heuristic	I-Algorithm
,	O
static	O
exchange	O
evaluation	O
,	O
quiescence	B-General_Concept
search	I-General_Concept
,	O
alpha-beta	B-Algorithm
pruning	I-Algorithm
,	O
a	O
transposition	B-General_Concept
table	I-General_Concept
,	O
a	O
refutation	O
table	O
,	O
an	O
evaluation	O
cache	O
,	O
selective	O
extensions	O
,	O
recursive	O
null-move	O
search	O
,	O
and	O
many	O
other	O
features	O
(	O
)	O
.	O
</s>
<s>
Crafty	B-Application
was	O
one	O
of	O
the	O
programs	O
included	O
in	O
the	O
SPEC	O
CPU2000	O
benchmark	O
test	O
.	O
</s>
<s>
It	O
is	O
also	O
included	O
as	O
an	O
additional	O
engine	O
in	O
Fritz	B-Application
.	O
</s>
