In Defense of Rajlich and Rybka

In early 2011, Vasik Rajlich was accused by the International Computer Games Association (ICGA) of plagiarism in writing his famous chess program Rybka, he was stripped of the world championship titles won with Rybka from 2007 to 2010, and banned for life from ICGA events. (Other than that, I think they liked him.)

It has been quite a while now, but there's a new and vigorous defense of Rajlich by one Dr. Søren Riis against what the author considers ICGA overreach. Two parts are out now (there's a third part coming soon), and they can be read here and here. He makes some interesting points, and it's good that Rajlich has someone defending him.

Thoughts?

Rybka Disqualified and Banned from Computer World Championships

Some time ago I mentioned the accusations that Vas Rajlich, Rybka's programmer, had based his program on the chess engine "Fruit". Since then the International Computer Games Association (ICGA) has investigated the claims, and concluded in a 5-0 decision that Rajlich was guilty not only of improperly taking code from Fruit but from Crafty as well. They write that

We are convinced that the evidence against Vasik Rajlich is both overwhelming in its volume and beyond reasonable question in its nature. Vasik Rajlich is guilty of plagiarizing the programs Crafty and Fruit, and has violated the ICGA’s tournament rules with respect to the World Computer Chess Championships in the years 2006, 2007, 2008, 2009 and 2010.

As a result, Rajlich is banned for life from the World Computer Chess Championship and all other ICGA events, and Rybka's championships in 2007-2010 are vacated, along with the Rybka predecessors's =2nd finish in 2006. Strong punishment, but appropriate if they are right about the evidence.

Much more, here.

TCEC Season 3 is Underway

For fans of computer-computer matches, the third season of Martin Thoresen's TCEC (Thoresen Chess Engines Competition) is underway. Information on how this season's competition is arranged is here, while the live broadcast (and a list of the participating computers, their ratings and their scores) is here.

Rybka vs. Houdini

For those who like to follow computer vs. computer matches, Rybka and Houdini will have a match to close the second season of engine competitions on Martin Thoresen's TCEC website. The fun starts Tuesday at 14:00 Central European Time.

The Rybka Controversy in the Mainstream Media

At least the mainstream German media. There's a report on the Rybka controversies (Fruit-to-Rybka, and Rybka-to-Ippolit-to-Houdini) in Der Spiegel (in German, but you can see what Google Translate has done it with it, here). Nothing new, really, but as so often happens chess generally makes the news in the West only after something strange, scandalous or salacious has occurred.

An Open Letter from Programmers on the Rybka-Fruit Issue

You can find it here, and it's not good news for Vas Rajlich and the Rybka side. There are some big names among the signatories (maybe they're all big names, but even I as an outsider to that community recognize some of the names), and I doubt that they can all be dismissed on the grounds of professional jealousy or something like that. Nevertheless, it must be emphasized that this letter does not constitute legal proof. All the same, I wonder: what's the best program out there that doesn't have some sort of direct or indirect taint?

David Levy on Cloned Chess Engines

Here. Levy condemns the practice, takes an inconclusive look at some of the controversies around Rybka, and then calls for help in setting up a forum to investigate claims of cloning.

A Look at Rybka 4 - Houdini 1.5a, Game 1

A while ago I reported that the free program Houdini 1.5a defeated the king of the commercial programs, Rybka 4, by a 23.5-16.5 score in a recent match. Many people, both on my blog and elsewhere, were especially impressed by Houdini's play in the first game of that match, and I can't blame them! Houdini sacrificed three pawns for play, and the end result was an overwhelming initiative. You can have a look at the game, with my comments, here.

Houdini 1.5a Defeats Rybka 4: 23.5-16.5

More on this site, somewhere. Assuming this result is meaningful*, it's not clear if this is good news or bad news for chess fans. Superficially, it's great news, because it costs money to buy Rybka while anyone can freely download Houdini. BUT: There seems to be a lot of cannibalizing going on among engines** (certainly such accusations are widespread), and if it's true that the free programs are ripping off code and concepts from the for-profit engines, it's likely that sooner or later the for-profit people will simply leave. Then the cannibals will have to do their own work, and with no financial incentive or notoriety to inspire them, the field will stagnate. Then it's not only a pity for the legitimate programmers whose work and financial opportunities were stolen, but for the broad chess community as well.

* There are reasons why it may not be so significant: the computers may have used truncated or common books, and a 40 game match, while not trivial, doesn't guarantee that Houdini is the stronger engine. Still, the evidence that's there, of whatever quality, is in Houdini's favor.

** As far as I know, no one has accused Houdini of pirating code from a closed-source engines, but its author has acknowledged being influenced by engines that have allegedly done so.

More Computer Chess Controversy

Somewhere around a year ago there was controversy about a series of programs that allegedly stole pieces of code from Rybka; now there's some controversy (or renewed controversy - I remember seeing something about this last year) as to the degree to which Rybka, at least in its earlier insilicarnation, depended on the chess engine Fruit. This forwarded letter by Fruit's programmer seems to be the instigator of the latest salvo.

I have no idea who, if anyone, is guilty of anything in this matter, and as a legal matter all the accusees should be considered innocent until proven guilty. I am curious about some points, however, like what counts as learning from a program as opposed to stealing intellectual property. If one uses someone's algorithm but expresses it in different code or in a different computer language, is it considered theft from a legal point of view? What about the moral point of view, from within the software community? And as a practical matter for those who want to take the highest possible road, are there any chess engines out there that are competitive and don't involve some "borrowing"?