<s>
FreeCell	B-Application
is	O
a	O
solitaire	O
card	O
game	O
played	O
using	O
the	O
standard	O
52-card	O
deck	O
.	O
</s>
<s>
Although	O
software	O
implementations	O
vary	O
,	O
most	O
versions	O
label	O
the	O
hands	O
with	O
a	O
number	O
(	O
derived	O
from	O
the	O
seed	O
value	O
used	O
by	O
the	O
random	B-Algorithm
number	I-Algorithm
generator	I-Algorithm
to	O
shuffle	O
the	O
cards	O
)	O
.	O
</s>
<s>
Microsoft	O
has	O
included	O
a	O
FreeCell	B-Application
computer	I-Application
game	I-Application
with	O
every	O
release	O
of	O
the	O
Windows	O
operating	O
system	O
since	O
1995	O
,	O
greatly	O
contributing	O
to	O
the	O
game	O
's	O
popularity	O
among	O
users	O
of	O
personal	O
computers	O
,	O
even	O
leading	O
to	O
the	O
creation	O
of	O
several	O
websites	O
devoted	O
to	O
FreeCell	B-Application
.	O
</s>
<s>
Microsoft	B-Application
FreeCell	I-Application
is	O
so	O
definitive	O
for	O
many	O
FreeCell	B-Application
players	O
that	O
many	O
other	O
software	O
implementations	O
strive	O
for	O
compatibility	O
with	O
its	O
random	B-Algorithm
number	I-Algorithm
generator	I-Algorithm
in	O
order	O
to	O
replicate	O
its	O
numbered	O
hands	O
.	O
</s>
<s>
Deal	O
number	O
11982	O
from	O
the	O
Windows	O
version	O
of	O
FreeCell	B-Application
is	O
an	O
example	O
of	O
an	O
unsolvable	O
FreeCell	B-Application
deal	O
,	O
the	O
only	O
deal	O
among	O
the	O
original	O
"	O
Microsoft	O
32,000	O
"	O
which	O
is	O
unsolvable	O
.	O
</s>
<s>
One	O
of	O
the	O
oldest	O
ancestors	O
of	O
FreeCell	B-Application
is	O
Eight	O
Off	O
.	O
</s>
<s>
In	O
the	O
June	O
1968	O
edition	O
of	O
Scientific	O
American	O
,	O
Martin	O
Gardner	O
described	O
in	O
his	O
"	O
Mathematical	O
Games	O
"	O
column	O
a	O
game	O
by	O
C	O
.	O
L	O
.	O
Baker	O
that	O
is	O
similar	O
to	O
FreeCell	B-Application
,	O
except	O
that	O
cards	O
on	O
the	O
tableau	O
are	O
built	O
by	O
suit	O
rather	O
than	O
by	O
alternate	O
colors	O
.	O
</s>
<s>
FreeCell	B-Application
's	O
origins	O
may	O
date	O
back	O
even	O
further	O
to	O
1945	O
and	O
to	O
a	O
Scandinavian	O
game	O
called	O
Napoleon	O
in	O
St.	O
Helena	O
(	O
not	O
the	O
solitaire	O
game	O
Napoleon	O
at	O
St	O
Helena	O
,	O
also	O
known	O
as	O
Forty	O
Thieves	O
)	O
.	O
</s>
<s>
Paul	O
Alfille	O
changed	O
Baker	O
's	O
Game	O
by	O
making	O
cards	O
build	O
according	O
to	O
alternate	O
colors	O
,	O
thus	O
creating	O
FreeCell	B-Application
.	O
</s>
<s>
He	O
implemented	O
the	O
first	O
computerised	O
version	O
as	O
a	O
medical	O
student	O
at	O
the	O
University	O
of	O
Illinois	O
,	O
in	O
the	O
TUTOR	B-Language
programming	I-Language
language	I-Language
for	O
the	O
PLATO	B-Operating_System
educational	O
computer	O
system	O
in	O
1978	O
.	O
</s>
<s>
Alfille	O
was	O
able	O
to	O
display	O
easily	O
recognizable	O
graphical	O
images	O
of	O
playing	O
cards	O
on	O
the	O
monochrome	O
display	O
on	O
the	O
PLATO	B-Operating_System
systems	I-Operating_System
.	O
</s>
<s>
This	O
original	O
FreeCell	B-Application
environment	O
allowed	O
games	O
with	O
4	O
–	O
10	O
columns	O
and	O
1	O
–	O
10	O
cells	O
in	O
addition	O
to	O
the	O
standard	O
game	O
.	O
</s>
<s>
Paul	O
Alfille	O
described	O
this	O
early	O
FreeCell	B-Application
environment	O
in	O
more	O
detail	O
in	O
an	O
interview	O
from	O
2000	O
.	O
</s>
<s>
In	O
2012	O
,	O
researchers	O
used	O
evolutionary	O
computation	O
methods	O
to	O
create	O
winning	O
FreeCell	B-Application
players	O
.	O
</s>
<s>
Other	O
solitaire	O
games	O
related	O
to	O
or	O
inspired	O
by	O
FreeCell	B-Application
include	O
Seahaven	O
Towers	O
,	O
Penguin	O
,	O
Stalactites	O
,	O
ForeCell	O
,	O
Antares	O
(	O
a	O
cross	O
with	O
Scorpion	O
)	O
.	O
</s>
<s>
The	O
FreeCell	B-Application
game	O
has	O
a	O
constant	O
number	O
of	O
cards	O
.	O
</s>
<s>
To	O
perform	O
an	O
interesting	O
complexity	O
analysis	O
one	O
must	O
construct	O
a	O
generalized	O
version	O
of	O
the	O
FreeCell	B-Application
game	O
with	O
cards	O
.	O
</s>
<s>
This	O
generalized	O
version	O
of	O
the	O
game	O
is	O
NP-complete	O
;	O
it	O
is	O
unlikely	O
that	O
any	O
algorithm	O
more	O
efficient	O
than	O
a	O
brute-force	O
search	O
exists	O
that	O
can	O
find	O
solutions	O
for	O
arbitrary	O
generalized	O
FreeCell	B-Application
configurations	O
.	O
</s>
