<s>
Rybka	B-Application
is	O
a	O
computer	B-Application
chess	I-Application
engine	O
designed	O
by	O
International	O
Master	O
Vasik	O
Rajlich	O
.	O
</s>
<s>
Around	O
2011	O
,	O
Rybka	B-Application
was	O
one	O
of	O
the	O
top-rated	O
engines	O
on	O
chess	B-Application
engine	I-Application
rating	O
lists	O
and	O
won	O
many	O
computer	B-Application
chess	I-Application
tournaments	O
.	O
</s>
<s>
After	O
Rybka	B-Application
won	O
four	O
consecutive	O
World	O
Computer	B-Application
Chess	I-Application
Championships	O
from	O
2007	O
to	O
2010	O
,	O
it	O
was	O
stripped	O
of	O
these	O
titles	O
after	O
the	O
International	O
Computer	O
Games	O
Association	O
concluded	O
in	O
June	O
2011	O
that	O
Rybka	B-Application
was	O
plagiarized	O
from	O
both	O
the	O
Crafty	B-Application
and	O
the	O
Fruit	B-Application
chess	B-Application
engines	I-Application
and	O
so	O
failed	O
to	O
meet	O
their	O
originality	O
requirements	O
.	O
</s>
<s>
In	O
2015	O
,	O
,	O
following	O
a	O
complaint	O
put	O
forward	O
by	O
Vasik	O
Rajlich	O
and	O
chess	B-Application
engine	I-Application
developer	O
and	O
games	O
publisher	O
Chris	O
Whittington	O
regarding	O
ethical	O
breaches	O
during	O
internal	O
disciplinary	O
proceedings	O
,	O
ruled	O
the	O
ICGA	O
guilty	O
and	O
sanctioned	O
ICGA	O
with	O
a	O
warning	O
.	O
</s>
<s>
Subsequently	O
,	O
ChessBase	O
has	O
published	O
Rybka	B-Application
to	O
produce	O
Fritz	B-Application
15	O
released	O
in	O
late	O
2015	O
and	O
Fritz	B-Application
16	O
released	O
in	O
late	O
2017	O
.	O
</s>
<s>
The	O
word	O
rybka	B-Application
,	O
pronounced	O
in	O
Czech	O
,	O
means	O
little	O
fish	O
in	O
Czech	O
,	O
Polish	O
,	O
and	O
in	O
many	O
other	O
Slavic	O
languages	O
.	O
</s>
<s>
Vasik	O
Rajlich	O
was	O
once	O
asked	O
in	O
an	O
interview	O
by	O
Alexander	O
Schmidt	O
,	O
"	O
Did	O
you	O
choose	O
the	O
name	O
Rybka	B-Application
because	O
your	O
program	O
always	O
slipped	O
out	O
of	O
your	O
hands	O
like	O
a	O
little	O
fish	O
?	O
"	O
</s>
<s>
He	O
replied	O
,	O
"	O
As	O
for	O
the	O
name	O
Rybka	B-Application
–	O
I	O
am	O
sorry	O
but	O
this	O
will	O
remain	O
my	O
private	O
secret.	O
"	O
</s>
<s>
Rybka	B-Application
is	O
a	O
closed-source	O
program	O
,	O
but	O
still	O
some	O
details	O
have	O
been	O
revealed	O
:	O
Rybka	B-Application
uses	O
a	O
bitboard	B-Application
representation	B-General_Concept
,	O
and	O
is	O
an	O
alpha-beta	B-Algorithm
searcher	O
with	O
a	O
relatively	O
large	O
aspiration	O
window	O
.	O
</s>
<s>
Several	O
members	O
of	O
the	O
Rybka	B-Application
team	O
are	O
strong	O
chess	B-Application
players	O
:	O
Vasik	O
Rajlich	O
,	O
the	O
main	O
author	O
of	O
Rybka	B-Application
is	O
an	O
International	O
Master	O
(	O
IM	O
)	O
.	O
</s>
<s>
GM	O
Larry	O
Kaufman	O
is	O
the	O
2008	O
Senior	O
Chess	B-Application
World	O
Champion	O
,	O
and	O
from	O
version	O
2.3	O
through	O
version	O
3	O
was	O
in	O
primary	O
charge	O
of	O
the	O
evaluation	O
function	O
.	O
</s>
<s>
Iweta	O
Rajlich	O
,	O
Vasik	O
Rajlich	O
's	O
wife	O
and	O
the	O
main	O
Rybka	B-Application
tester	O
is	O
a	O
Women	O
's	O
GM	O
(	O
WGM	O
)	O
and	O
IM	O
.	O
</s>
<s>
Jeroen	O
Noomen	O
(	O
who	O
used	O
to	O
work	O
on	O
Rebel	B-Application
)	O
and	O
Dagh	O
Nielsen	O
were	O
the	O
authors	O
of	O
its	O
opening	O
book	O
–	O
the	O
latter	O
is	O
one	O
of	O
the	O
world	O
's	O
top	O
freestyle	B-General_Concept
chess	I-General_Concept
players	O
.	O
</s>
<s>
Vasik	O
Rajlich	O
started	O
working	O
on	O
his	O
chess	B-Application
program	I-Application
at	O
the	O
beginning	O
of	O
2003	O
.	O
</s>
<s>
The	O
first	O
Rybka	B-Application
beta	O
was	O
released	O
on	O
December	O
2	O
,	O
2005	O
.	O
</s>
<s>
The	O
appearance	O
of	O
the	O
free	O
Rybka	B-Application
1	O
beta	O
and	O
the	O
first	O
commercial	O
version	O
,	O
Rybka	B-Application
1	O
end	O
of	O
2005	O
was	O
a	O
sensation	O
,	O
and	O
Rybka	B-Application
soon	O
became	O
the	O
dominating	O
program	O
leading	O
rating	O
lists	O
by	O
a	O
huge	O
margin	O
.	O
</s>
<s>
In	O
January	O
2004	O
,	O
Rybka	B-Application
participated	O
in	O
the	O
6th	O
Programmers	O
Computer	B-Application
Chess	I-Application
Tournament	O
(	O
CCT6	O
)	O
event	O
,	O
placing	O
53rd	O
out	O
of	O
54	O
competers	O
,	O
losing	O
5	O
games	O
,	O
drawing	O
3	O
,	O
and	O
beating	O
the	O
last-place	O
finisher	O
who	O
had	O
0	O
points	O
(	O
Tohno	O
)	O
.	O
</s>
<s>
In	O
April	O
2004	O
,	O
Rybka	B-Application
participated	O
in	O
Chess	B-Application
War	O
V	O
conducted	O
by	O
Olivier	O
Deville	O
,	O
finishing	O
23rd	O
in	O
the	O
D	O
Division	O
.	O
</s>
<s>
In	O
April	O
2004	O
,	O
Rybka	B-Application
participated	O
in	O
the	O
Swiss	O
System	O
Season	O
3	O
by	O
Claude	O
Dubois	O
,	O
</s>
<s>
Rybka	B-Application
participated	O
in	O
Chess	B-Application
War	O
VI	O
finishing	O
42nd	O
in	O
the	O
D	O
Division	O
.	O
</s>
<s>
Rybka	B-Application
participated	O
in	O
Chess	B-Application
War	O
VII	O
finishing	O
48th	O
in	O
the	O
C	O
Division	O
.	O
</s>
<s>
Rybka	B-Application
participated	O
in	O
AEGT	O
round	O
3	O
,	O
scoring	O
89	O
wins	O
,	O
28	O
losses	O
and	O
15	O
draws	O
.	O
</s>
<s>
In	O
December	O
2005	O
,	O
Rybka	B-Application
participated	O
in	O
the	O
15th	O
International	O
Paderborn	O
Computer	B-Application
Chess	I-Application
Championship	O
.	O
</s>
<s>
Rybka	B-Application
won	O
the	O
tournament	O
with	O
a	O
score	O
of	O
5½	O
points	O
out	O
of	O
7	O
,	O
ahead	O
of	O
other	O
engines	O
such	O
as	O
Gandalf	O
,	O
Zappa	B-Application
,	O
Spike	O
,	O
Shredder	B-Application
and	O
Fruit	B-Application
.	O
</s>
<s>
On	O
CCT8	O
in	O
February	O
2006	O
,	O
Rybka	B-Application
won	O
with	O
a	O
score	O
of	O
8	O
out	O
of	O
9	O
,	O
going	O
undefeated	O
.	O
</s>
<s>
In	O
the	O
April	O
2006	O
PAL/CSS	O
Freestyle	B-General_Concept
main	O
tournament	O
,	O
an	O
unaided	O
Rybka	B-Application
1.1	O
took	O
first	O
place	O
.	O
</s>
<s>
In	O
the	O
final	O
tournament	O
,	O
Rybka	B-Application
1.1	O
finished	O
in	O
second	O
and	O
third	O
place	O
,	O
behind	O
Hydra	B-Architecture
.	O
</s>
<s>
In	O
the	O
6th	O
Leiden	O
ICT	O
in	O
May	O
2006	O
,	O
Rybka	B-Application
won	O
with	O
a	O
score	O
of	O
8½	O
out	O
of	O
9	O
,	O
ahead	O
of	O
Sjeng	B-Application
,	O
Gandalf	O
and	O
Shredder	B-Application
.	O
</s>
<s>
At	O
the	O
14th	O
World	O
Computer	B-Application
Chess	I-Application
Championship	O
in	O
Turin	O
,	O
Italy	O
in	O
May	O
2006	O
,	O
Rybka	B-Application
,	O
playing	O
under	O
the	O
name	O
Rajlich	O
,	O
finished	O
second	O
,	O
tied	O
with	O
Shredder	B-Application
,	O
after	O
Junior	B-Application
,	O
the	O
winning	O
2006	O
World	O
champion	O
.	O
</s>
<s>
In	O
the	O
June	O
2006	O
PAL/CSS	O
Freestyle	B-General_Concept
main	O
tournament	O
,	O
the	O
Rybka	B-Application
team	O
,	O
playing	O
under	O
the	O
handle	O
Rajlich	O
,	O
tied	O
for	O
first	O
place	O
with	O
Intagrand	O
.	O
</s>
<s>
In	O
the	O
final	O
,	O
the	O
Rybka	B-Application
team	O
took	O
clear	O
first	O
place	O
,	O
a	O
point	O
ahead	O
of	O
the	O
field	O
.	O
</s>
<s>
All	O
8	O
qualifiers	O
for	O
to	O
the	O
final	O
were	O
Rybka	B-Application
users	O
.	O
</s>
<s>
In	O
the	O
2006	O
Dutch	O
open	O
computer	B-Application
chess	I-Application
championship	O
,	O
Rybka	B-Application
2.2	O
finished	O
in	O
first	O
place	O
with	O
a	O
perfect	O
score	O
of	O
9	O
out	O
of	O
9	O
.	O
</s>
<s>
In	O
December	O
2006	O
,	O
Rybka	B-Application
participated	O
in	O
the	O
16th	O
International	O
Paderborn	O
Computer	B-Application
Chess	I-Application
Championship	O
.	O
</s>
<s>
Rybka	B-Application
won	O
the	O
tournament	O
with	O
a	O
score	O
of	O
6½	O
points	O
out	O
of	O
7	O
.	O
</s>
<s>
In	O
February	O
2007	O
,	O
Rybka	B-Application
participated	O
in	O
the	O
CCT9	O
and	O
won	O
with	O
6/7	O
.	O
</s>
<s>
In	O
the	O
7th	O
Leiden	O
ICT	O
in	O
May	O
2007	O
,	O
Rybka	B-Application
won	O
with	O
a	O
score	O
of	O
7½	O
out	O
of	O
9	O
,	O
ahead	O
of	O
Zappa	B-Application
and	O
HIARCS	B-Application
.	O
</s>
<s>
Rybka	B-Application
won	O
the	O
15th	O
World	O
Computer	B-Application
Chess	I-Application
Championship	O
in	O
June	O
2007	O
with	O
a	O
score	O
of	O
10	O
out	O
of	O
11	O
.	O
</s>
<s>
The	O
Rybka	B-Application
team	O
,	O
playing	O
under	O
the	O
handle	O
Rajlich	O
,	O
won	O
the	O
June	O
2007	O
PAL/CSS	O
Freestyle	B-General_Concept
final	O
with	O
a	O
score	O
of	O
6/9	O
.	O
</s>
<s>
Later	O
that	O
year	O
it	O
won	O
again	O
the	O
Dutch	O
open	O
computer	B-Application
chess	I-Application
championship	O
,	O
scoring	O
8/9	O
.	O
</s>
<s>
In	O
January	O
2008	O
,	O
Rybka	B-Application
tied	O
for	O
first	O
place	O
in	O
CCT10	O
with	O
5.5/7	O
.	O
</s>
<s>
In	O
October	O
2008	O
,	O
Rybka	B-Application
won	O
the	O
16th	O
World	O
Computer	B-Application
Chess	I-Application
Championship	O
,	O
held	O
in	O
Beijing	O
,	O
China	O
,	O
scoring	O
8/9	O
.	O
</s>
<s>
A	O
month	O
later	O
Rybka	B-Application
won	O
the	O
27th	O
Open	O
Dutch	O
Computer	B-Application
Chess	I-Application
Championship	O
,	O
held	O
in	O
Leiden	O
,	O
scoring	O
a	O
perfect	O
9/9	O
.	O
</s>
<s>
In	O
March	O
2009	O
,	O
Rybka	B-Application
won	O
CCT11	O
with	O
7.5/9	O
and	O
the	O
17th	O
World	O
Computer	B-Application
Chess	I-Application
Championship	O
,	O
held	O
in	O
Pamplona	O
,	O
Spain	O
,	O
with	O
a	O
score	O
of	O
8/9	O
.	O
</s>
<s>
In	O
May	O
2010	O
,	O
Rybka	B-Application
won	O
the	O
International	O
Computer	B-Application
Chess	I-Application
Tournament	O
in	O
Leiden	O
with	O
8/9	O
.	O
</s>
<s>
In	O
March	O
2007	O
,	O
Rybka	B-Application
played	O
an	O
eight-game	O
match	O
against	O
GM	O
Roman	O
Dzindzichashvili	O
with	O
pawn	O
and	O
move	O
odds	O
.	O
</s>
<s>
The	O
result	O
was	O
4	O
–	O
4	O
,	O
after	O
two	O
Rybka	B-Application
wins	O
,	O
four	O
draws	O
and	O
two	O
losses	O
.	O
</s>
<s>
Whilst	O
Rybka	B-Application
has	O
in	O
March	O
2007	O
with	O
GM	O
Jaan	O
Ehlvest	O
which	O
involved	O
giving	O
pawn	O
odds	O
to	O
the	O
human	O
,	O
GM	O
Larry	O
Kaufman	O
of	O
the	O
Rybka	B-Application
team	O
has	O
pledged	O
his	O
own	O
money	O
to	O
a	O
human	O
GM	O
who	O
can	O
beat	O
Rybka	B-Application
in	O
a	O
six-game	O
.	O
</s>
<s>
GM	O
Jaan	O
Ehlvest	O
was	O
again	O
chosen	O
to	O
play	O
Rybka	B-Application
,	O
getting	O
twice	O
the	O
thinking	O
time	O
and	O
white	O
every	O
match	O
,	O
with	O
Rybka	B-Application
having	O
only	O
a	O
three-move	O
opening	O
book	O
,	O
limited	O
(	O
512MB	O
)	O
hash	O
size	O
,	O
and	O
no	O
endgame	O
tablebases	O
(	O
the	O
match	O
being	O
dubbed	O
"	O
Everything	O
but	O
a	O
pawn	O
"	O
)	O
.	O
</s>
<s>
The	O
match	O
,	O
again	O
played	O
in	O
2007	O
,	O
ended	O
4.5	O
–	O
1.5	O
after	O
three	O
Rybka	B-Application
wins	O
and	O
three	O
draws	O
.	O
</s>
<s>
In	O
September	O
2008	O
,	O
Rybka	B-Application
played	O
an	O
odds	O
match	O
against	O
Vadim	O
Milov	O
,	O
its	O
strongest	O
opponent	O
yet	O
in	O
an	O
odds	O
match	O
.	O
</s>
<s>
Finally	O
they	O
played	O
four	O
games	O
at	O
odds	O
of	O
the	O
exchange	O
(	O
Rybka	B-Application
removed	O
a1	O
rook	O
,	O
Milov	O
b8	O
knight	O
)	O
;	O
here	O
Rybka	B-Application
drew	O
three	O
times	O
and	O
lost	O
once	O
.	O
</s>
<s>
In	O
September	O
2007	O
,	O
Zappa	B-Application
defeated	O
Rybka	B-Application
in	O
a	O
match	O
,	O
–	O
.	O
</s>
<s>
However	O
,	O
due	O
to	O
an	O
incorrect	O
evaluation	O
by	O
the	O
Rybka	B-Application
engine	O
,	O
at	O
move	O
109	O
it	O
moved	O
a	O
pawn	O
to	O
avoid	O
a	O
draw	O
(	O
even	O
though	O
Zappa	B-Application
could	O
,	O
and	O
did	O
,	O
immediately	O
take	O
the	O
pawn	O
)	O
,	O
thus	O
resetting	O
the	O
counter	O
for	O
that	O
rule	O
.	O
</s>
<s>
The	O
loss	O
of	O
the	O
pawn	O
eventually	O
allowed	O
Zappa	B-Application
to	O
whittle	O
away	O
Rybka	B-Application
's	O
defenses	O
and	O
win	O
the	O
game	O
.	O
</s>
<s>
Then	O
in	O
game	O
9	O
,	O
Rybka	B-Application
was	O
3	O
pawns	O
up	O
with	O
a	O
totally	O
won	O
position	O
,	O
but	O
played	O
a	O
horrific	O
blunder	O
on	O
move	O
71	O
,	O
"	O
the	O
worst	O
blunder	O
in	O
modern	O
computer	B-Application
chess	I-Application
"	O
,	O
as	O
it	O
lacked	O
sufficient	O
knowledge	O
to	O
see	O
a	O
draw	O
would	O
ensue	O
by	O
opposite-color	O
bishops	O
.	O
</s>
<s>
Zappa	B-Application
had	O
this	O
knowledge	O
,	O
took	O
advantage	O
,	O
and	O
drew	O
the	O
game	O
.	O
</s>
<s>
Anthony	B-Application
Cozzie	I-Application
thanked	O
his	O
operator	O
Erdogan	O
Gunes	O
for	O
having	O
the	O
wherewithal	O
to	O
stay	O
until	O
the	O
end	O
in	O
these	O
two	O
games	O
,	O
rather	O
than	O
agree	O
to	O
a	O
draw	O
in	O
game	O
4	O
or	O
resign	O
in	O
game	O
9	O
.	O
</s>
<s>
The	O
match	O
came	O
about	O
after	O
Vasik	O
Rajlich	O
made	O
a	O
$	O
100,000	O
publicity	O
challenge	O
to	O
the	O
FIDE	O
champion	O
Fritz	B-Application
or	O
Junior	B-Application
,	O
even	O
offering	O
odds	O
of	O
a	O
game	O
in	O
a	O
24-game	O
match	O
(	O
13	O
points	O
)	O
.	O
</s>
<s>
But	O
negotiations	O
between	O
Rybka	B-Application
and	O
Junior	B-Application
broke	O
down	O
due	O
to	O
disputes	O
over	O
on-site	O
machines	O
.	O
</s>
<s>
The	O
match	O
was	O
changed	O
to	O
10	O
games	O
against	O
Zappa	B-Application
,	O
with	O
$	O
10,000	O
the	O
amount	O
eventually	O
paid	O
to	O
the	O
winner	O
.	O
</s>
<s>
Rybka	B-Application
3	I-Application
was	O
released	O
on	O
August	O
6	O
,	O
2008	O
.	O
</s>
<s>
While	O
previous	O
versions	O
of	O
Rybka	B-Application
were	O
released	O
exclusively	O
by	O
Convekta	O
,	O
Rybka	B-Application
3	I-Application
was	O
released	O
by	O
both	O
Chessbase	O
and	O
Convekta	O
.	O
</s>
<s>
Although	O
still	O
a	O
UCI	B-General_Concept
engine	I-General_Concept
,	O
Rybka	B-Application
3	I-Application
has	O
extra	O
features	O
when	O
run	O
under	O
the	O
ChessBase	O
and	O
Convekta	O
user	O
interfaces	O
.	O
</s>
<s>
In	O
an	O
interview	O
with	O
Frank	O
Quisinsky	O
,	O
Vasik	O
Rajlich	O
revealed	O
plans	O
for	O
a	O
future	O
GUI	B-Application
that	O
would	O
"	O
properly	O
display	O
chess	B-Application
knowledge	O
to	O
the	O
user	O
"	O
most	O
likely	O
in	O
the	O
form	O
of	O
graphical	O
evaluation	O
of	O
the	O
pieces	O
on	O
the	O
board	O
.	O
</s>
<s>
The	O
GUI	B-Application
,	O
named	O
Aquarium	O
,	O
has	O
been	O
released	O
by	O
ChessOK	O
(	O
formerly	O
known	O
as	O
Convekta	O
)	O
.	O
</s>
<s>
Rybka	B-Application
4	O
was	O
released	O
May	O
26	O
,	O
2010	O
.	O
</s>
<s>
Vasik	O
Rajlich	O
has	O
given	O
the	O
following	O
information	O
at	O
the	O
Rybka	B-Application
forum	O
:	O
</s>
<s>
Rybka	B-Application
4	O
is	O
a	O
normal	O
UCI	B-General_Concept
engine	I-General_Concept
,	O
without	O
copy	O
protection	O
.	O
</s>
<s>
Full	O
chess	B-Application
analysis	O
packages	O
which	O
include	O
Rybka	B-Application
4	O
will	O
be	O
made	O
by	O
ChessBase	O
(	O
www.chessbase.com	O
)	O
and	O
Convekta/ChessOK	O
(	O
www.chessok.com	O
)	O
.	O
</s>
<s>
Plain	O
Rybka	B-Application
4	O
UCI	O
without	O
GUI	B-Application
for	O
download	O
only	O
is	O
available	O
from	O
RybkaChess	O
(	O
www.rybkachess.com	O
)	O
.	O
</s>
<s>
All	O
of	O
these	O
versions	O
of	O
Rybka	B-Application
4	O
will	O
be	O
identical	O
and	O
can	O
be	O
used	O
in	O
any	O
UCI-compliant	O
GUI	B-Application
.	O
</s>
<s>
Vasik	O
Rajlich	O
has	O
now	O
released	O
which	O
is	O
a	O
special	O
version	O
of	O
Rybka	B-Application
(	O
4+	O
or	O
cluster	O
)	O
on	O
very	O
powerful	O
hardware	O
/	O
clusters	O
run	O
by	O
Lukas	O
Cimiotti	O
.	O
</s>
<s>
Upon	O
renting	O
one	O
has	O
access	O
to	O
the	O
Remote	O
Rybka	B-Application
from	O
one	O
's	O
PC	O
,	O
and	O
all	O
details	O
of	O
rentals	O
are	O
strictly	O
private	O
.	O
</s>
<s>
Information	O
from	O
the	O
last	O
video	O
interview	O
by	O
Vasik	O
Rajlich	O
indicated	O
that	O
Rybka	B-Application
5	O
was	O
scheduled	O
to	O
arrive	O
anywhere	O
between	O
the	O
end	O
of	O
2011	O
and	O
the	O
first	O
half	O
of	O
2012	O
.	O
</s>
<s>
Early	O
private	O
Rybka	B-Application
engines	O
have	O
been	O
accused	O
of	O
being	O
a	O
clone	O
of	O
Crafty	B-Application
,	O
including	O
copying	O
specific	O
bugs	O
-	O
such	O
as	O
comparing	O
the	O
result	O
of	O
the	O
EvaluateMate	O
function	O
to	O
a	O
number	O
,	O
99999	O
,	O
that	O
it	O
could	O
not	O
possibly	O
return	O
-	O
and	O
unnecessary	O
code	O
(	O
"	O
there	O
is	O
no	O
earthly	O
reason	O
for	O
any	O
program	O
that	O
claimed	O
to	O
have	O
been	O
started	O
in	O
2003	O
to	O
have	O
such	O
code	O
,	O
other	O
than	O
that	O
it	O
was	O
mindlessly	O
copied	O
from	O
Crafty	B-Application
without	O
the	O
slightest	O
understanding	O
of	O
its	O
purpose	O
"	O
)	O
.	O
</s>
<s>
In	O
May	O
2007	O
,	O
a	O
new	O
chess	B-Application
engine	I-Application
called	O
Strelka	B-Application
(	O
Russian	O
for	O
"	O
arrow	O
"	O
)	O
appeared	O
on	O
the	O
scene	O
,	O
claimed	O
to	O
be	O
written	O
by	O
Yuri	O
Osipov	O
.	O
</s>
<s>
Soon	O
,	O
there	O
were	O
allegations	O
that	O
Strelka	B-Application
was	O
a	O
clone	O
of	O
Rybka	B-Application
1.0	O
beta	O
,	O
in	O
the	O
sense	O
that	O
it	O
was	O
a	O
reverse-engineered	O
and	O
slightly	O
modified	O
version	O
of	O
Rybka	B-Application
.	O
</s>
<s>
Several	O
players	O
found	O
Strelka	B-Application
to	O
yield	O
identical	O
analysis	O
to	O
Rybka	B-Application
in	O
a	O
variety	O
of	O
different	O
situations	O
,	O
even	O
having	O
the	O
same	O
bugs	O
and	O
weaknesses	O
in	O
some	O
cases	O
.	O
</s>
<s>
Osipov	O
,	O
however	O
,	O
stated	O
repeatedly	O
on	O
discussion	O
boards	O
that	O
Strelka	B-Application
was	O
based	O
on	O
Fruit	B-Application
,	O
not	O
Rybka	B-Application
,	O
and	O
that	O
any	O
similarities	O
was	O
either	O
because	O
Rybka	B-Application
also	O
was	O
based	O
on	O
Fruit	B-Application
,	O
or	O
because	O
he	O
had	O
tuned	O
the	O
evaluation	O
function	O
to	O
be	O
as	O
close	O
to	O
Rybka	B-Application
as	O
possible	O
.	O
</s>
<s>
With	O
the	O
release	O
of	O
Strelka	B-Application
2.0	O
beta	O
,	O
source	O
code	O
was	O
included	O
.	O
</s>
<s>
Rajlich	O
stated	O
that	O
the	O
source	O
made	O
it	O
"	O
obvious	O
"	O
that	O
Strelka	B-Application
2.0	O
beta	O
was	O
indeed	O
a	O
Rybka	B-Application
1.0	O
beta	O
clone	O
,	O
although	O
not	O
without	O
some	O
improvements	O
in	O
certain	O
areas	O
.	O
</s>
<s>
According	O
to	O
Victor	O
Zakharov	O
(	O
Convekta	O
company	O
)	O
in	O
his	O
review	O
for	O
Arena	O
chess	B-Application
website	O
:	O
"	O
I	O
consider	O
that	O
Yuri	O
Osipov	O
(	O
Ivanovich	O
)	O
is	O
real	O
name	O
.	O
</s>
<s>
And	O
he	O
also	O
has	O
some	O
contact	O
with	O
Yuri	O
Osipov	O
for	O
development	O
of	O
mobile	O
platforms	O
chess	B-Application
program	I-Application
.	O
</s>
<s>
Fruit	B-Application
author	O
Fabien	O
Letouzey	O
expressed	O
in	O
the	O
open	O
letter	O
mentioned	O
above	O
that	O
Strelka	B-Application
2.0	O
beta	O
is	O
a	O
Fruit	B-Application
derivative	O
with	O
some	O
minor	O
changes	O
.	O
</s>
<s>
IPPOLIT	B-Application
,	O
RobboLito	O
,	O
Igorrit	O
,	O
IvanHoe	O
,	O
FireBird	O
and	O
Fire	O
are	O
a	O
series	O
of	O
strong	O
open	O
source	O
chess	B-Application
programs	I-Application
,	O
originally	O
developed	O
by	O
a	O
team	O
of	O
anonymous	O
programmers	O
who	O
call	O
themselves	O
the	O
Decembrists	O
,	O
after	O
the	O
Decembrist	O
revolt	O
.	O
</s>
<s>
Vasik	O
Rajlich	O
has	O
stated	O
that	O
IPPOLIT	B-Application
is	O
a	O
decompiled	B-Application
version	O
of	O
Rybka	B-Application
,	O
and	O
that	O
the	O
people	O
involved	O
kept	O
him	O
informed	O
of	O
their	O
progress	O
via	O
email	O
.	O
</s>
<s>
Rybka	B-Application
has	O
been	O
accused	O
of	O
being	O
based	O
on	O
Fruit	B-Application
,	O
but	O
Rajlich	O
has	O
denied	O
this	O
categorically	O
,	O
saying	O
that	O
Rybka	B-Application
is	O
100%	O
original	O
at	O
the	O
source	O
code	O
level	O
.	O
</s>
<s>
Further	O
allegations	O
of	O
violating	O
the	O
GPL	B-License
have	O
been	O
brought	O
forward	O
by	O
chess	B-Application
programmer	O
based	O
on	O
a	O
new	O
decompilation	B-Application
effort	O
and	O
a	O
one-year	O
study	O
of	O
the	O
Rybka	B-Application
1.0	O
executable	O
.	O
</s>
<s>
The	O
Fruit	B-Application
author	O
Fabien	O
Letouzey	O
has	O
since	O
appeared	O
from	O
a	O
5-year	O
absence	O
in	O
January	O
2011	O
and	O
published	O
an	O
open	O
letter	O
asking	O
for	O
more	O
information	O
regarding	O
Rybka	B-Application
and	O
GPL	B-License
violations	O
.	O
</s>
<s>
The	O
options	O
include	O
revoking	O
all	O
tournament	O
victories	O
of	O
Rybka	B-Application
by	O
Statute	O
3.h.iv	O
.	O
</s>
<s>
Fourteen	O
well-known	O
chess	B-Application
programmers	O
have	O
since	O
written	O
an	O
open	O
letter	O
to	O
David	O
Levy	O
,	O
Jaap	O
van	O
den	O
Herik	O
and	O
the	O
ICGA	O
board	O
stating	O
that	O
there	O
is	O
now	O
"	O
overwhelming	O
evidence	O
"	O
that	O
Rybka	B-Application
1.0	O
beta	O
(	O
the	O
first	O
strong	O
Rybka	B-Application
version	O
)	O
was	O
directly	O
derived	O
from	O
Fruit	B-Application
.	O
</s>
<s>
On	O
June	O
28	O
,	O
2011	O
,	O
the	O
International	O
Computer	O
Games	O
Association	O
(	O
ICGA	O
)	O
concluded	O
their	O
investigation	O
and	O
determined	O
that	O
Vasik	O
Rajlich	O
in	O
programming	O
Rybka	B-Application
had	O
plagiarized	O
two	O
other	O
chess	B-Application
software	I-Application
programs	O
:	O
Crafty	B-Application
and	O
Fruit	B-Application
.	O
</s>
<s>
According	O
to	O
ICGA	O
,	O
Vasik	O
Rajlich	O
failed	O
to	O
comply	O
with	O
the	O
ICGA	O
rule	O
that	O
each	O
computer	B-Application
chess	I-Application
program	O
must	O
be	O
the	O
original	O
work	O
of	O
the	O
entering	O
developer	O
and	O
those	O
"	O
whose	O
code	O
is	O
derived	O
from	O
or	O
including	O
game-playing	O
code	O
written	O
by	O
others	O
must	O
name	O
all	O
other	O
authors	O
,	O
or	O
the	O
source	O
of	O
such	O
code	O
,	O
in	O
their	O
submission	O
details	O
"	O
.	O
</s>
<s>
The	O
ICGA	O
regarded	O
Vasik	O
Rajlich	O
's	O
alleged	O
violation	O
as	O
the	O
most	O
serious	O
offence	O
that	O
a	O
chess	B-Application
programmer	O
and	O
ICGA	O
member	O
can	O
commit	O
with	O
respect	O
to	O
his	O
peers	O
and	O
to	O
the	O
ICGA	O
.	O
</s>
<s>
The	O
ICGA	O
sanction	O
for	O
Vasik	O
Rajlich	O
and	O
Rybka	B-Application
was	O
the	O
disqualification	O
from	O
the	O
World	O
Computer	B-Application
Chess	I-Application
Championship	O
(	O
WCCC	O
)	O
of	O
2006	O
,	O
2007	O
,	O
2008	O
,	O
2009	O
and	O
2010	O
.	O
</s>
<s>
In	O
addition	O
,	O
the	O
ICGA	O
demanded	O
that	O
Vasik	O
Rajlich	O
return	O
to	O
the	O
ICGA	O
the	O
four	O
replicas	O
of	O
the	O
Shannon	O
Trophy	O
presented	O
at	O
the	O
WCCC	O
in	O
2007	O
,	O
2008	O
,	O
2009	O
and	O
2010	O
and	O
all	O
prize	O
money	O
awarded	O
for	O
Rybka	B-Application
's	O
performances	O
in	O
those	O
events	O
.	O
</s>
<s>
On	O
publication	O
of	O
the	O
ICGA	O
verdict	O
and	O
sentence	O
,	O
extensive	O
disagreement	O
broke	O
out	O
on	O
Computer	B-Application
Chess	I-Application
Forums	O
,	O
centering	O
on	O
correct	O
application	O
of	O
Abstraction-Filtration-Comparison	O
test	O
,	O
the	O
differences	O
between	O
copying	O
ideas	O
and	O
copying	O
code	O
and	O
bias	O
in	O
investigation	O
.	O
</s>
<s>
Riis	O
,	O
a	O
computer	O
scientist	O
at	O
the	O
Queen	O
Mary	O
University	O
of	O
London	O
and	O
a	O
Rybka	B-Application
forum	O
moderator	O
,	O
was	O
critical	O
of	O
the	O
ICGA	O
's	O
decision	O
,	O
the	O
investigation	O
,	O
the	O
methods	O
on	O
which	O
the	O
investigation	O
was	O
based	O
,	O
and	O
the	O
bias	O
of	O
the	O
panel	O
members	O
and	O
Secretariat	O
.	O
</s>
<s>
Riis	O
argued	O
that	O
critical	O
portions	O
of	O
the	O
ICGA	O
panel	O
report	O
that	O
appeared	O
to	O
show	O
line-by-line	O
code	O
duplication	O
between	O
Rybka	B-Application
and	O
Fruit	B-Application
were	O
misleading	O
or	O
falsified	O
,	O
and	O
objected	O
to	O
the	O
panel	O
's	O
and	O
Secretariat	O
's	O
composition	O
,	O
suggesting	O
that	O
it	O
consisted	O
almost	O
exclusively	O
of	O
rival	O
chess	B-Application
programmers	O
who	O
had	O
a	O
conflict	O
of	O
interest	O
in	O
seeing	O
Rajlich	O
banned	O
from	O
competition	O
in	O
order	O
to	O
interrupt	O
his	O
unbroken	O
domination	O
of	O
competitive	O
computer	B-Application
chess	I-Application
.	O
</s>
<s>
In	O
2012	O
,	O
Vasik	O
Rajlich	O
filed	O
a	O
complaint	O
against	O
the	O
ICGA	O
decisions	O
,	O
process	O
and	O
bias	O
to	O
the	O
FIDE	O
Ethics	O
Commission	O
,	O
as	O
co-signed	O
by	O
Soren	O
Riis	O
,	O
Ed	B-Application
Schröder	I-Application
and	O
Chris	O
Whittington	O
.	O
</s>
<s>
Cock	O
de	O
Gorter	O
,	O
Chairman	O
of	O
Dutch	O
Computer	B-Application
Chess	I-Application
Association	O
(	O
CSVN	O
)	O
wrote	O
:	O
</s>
<s>
Rybka	B-Application
competed	O
in	O
the	O
2012	O
CSVN	O
event	O
(	O
ICT	O
)	O
and	O
won	O
.	O
</s>
