Chess crown stripped in plagiarism furore
Computer champion copied code
Knights and pawns are being brandished in the rarified world of computer chess, with program Rybka and its developer Vasik Rajlich stripped of the world title on a charge of plagiarism.
According to Chessvibes, the controversy has been simmering since February this year, when Rybka lost in a game against a rival program, Houdini. In response to accusations that Rybka used code from other chess engines, the International Computer Games Association put together a panel to investigate.
Now, the ICGA has decided that Rybka was cloned from the open source Crafty and Fruit chess programs, with its panel deciding to strip Rajlich of his World Computer Chess Championship titles for 2007 to 2010, and his shared second place for 2006.
The letter from the ICGA, published by Chessvibes, says that although Rajlich repeatedly denied plagiarizing other programmers’ work, he didn’t offer “any kind of defence to the allegations”.
Moreover, the committee has accused Rajlich of breaching the open source licenses of both Crafty and Fruit, by basing Rybka on these open-source programs, but not offering the source code to users. ®
t's the SCOundrel gambit aka the Sicillian Attack
An unusual opening which can cause the game to go on for seven years but ultimately the initial weakness of "no evidence" leads to checkmate. Most of the moves take place off the board and include claiming to have used deep analysis that can't be revealed and claimng "all your moves are belong to us" and "nice restaurant you've got there"
anonymous because the the icon looks like a Venician carnevale mask and Venice is about as far away as you can get from Sicilly and remain in Italy
No evidence offered
@Steve Brooks: "There is no other defense he can present except that he didn't copy the other program."
A reasonable defence would be substantiated. Software doesn't pop out of the ether - he should have a supporting timeline for development, which may include code repository checkins, backups, etc. which demonstrate the evolution of his code. It's very common to have research documents, planning documents, pseudocode, algorithm diagrams, or other types of modelling. Simply saying, "I wrote it", without offering any evidence of your work is suspicious.
There's quite a lot of evidence to say that he did copy the code
"Nearly the entire evaluation function is derived from Fruit. This includes
the formulas for calculating piece-square tables, methods and features of evaluating
piece mobility, rook king file proximity, rook and queen on the 7th rank, and king safety. "
"Disassembly of the root search analysis indicates nearly identical code and
variables, even including the ordering of the variables."
"Pre-Rybka 1.6.1 contains much identical code to Crafty, even including large
blocks of code with obsolete code inside them, and code that performs tests that make
no sense today (code that was left in Crafty by accident, by Robert Hyatt, also shows
up in Rybka 1.6.1). It is inconceivable that a second author could duplicate this code
purely by chance. At least hundreds of lines of code appear to be copied."