I agree that it would be nice to get the Fruit timeline correct.

Fruit 2.x was in Sept. 2005. Rybka 1.0 beta, Dec. of that year. Commercial version of Fruit was available before commercial version of Rybka (I bought both as soon as they were available). Rybka 1.0 beta was modestly stronger than ...

Rybka 1.0 Beta and commercial Fruit are about the same Elo level in their 32-bit versions.

True, but ICGA aside, I'll point out that Rajlich didn't attempt to profit from Rybka until it had a significant Elo lead.

For the first point, the history of the development of Fruit seems to imply that ...

Elo is not much of a measure of "closeness" when talking about derivatives. Add null move to TSCP . This gains that at least 100 Elo I suspect, in an effort of about 5-10 lines. Are the resulting engines not "close" in the source code sense?

Generally speaking, an engine is probably not very good ...

Obviously, any engine playing 100 Elo above another is not "close" by any meaning of the term. -Carl

2. Each program must be the original work of the entering developers. Programming teams whose code is derived from or including game-playing code written by others must name all other authors, or the source of such code, in the details of their submission form. Programs which are discovered to be ...

That is I didn't mention Rybka 3 & 4 source code being released because there's no evidence to suggest Fruit traces. Especially in the case of version 4, prior to its release, the Rybka/Fruit debate was a hot topic -- so I doubt Vas would have been that negligent. Would it have mattered if version ...

Note, Rybka 3 & 4 are not mentioned because there hasn't been anything suggesting they contain Fruit code.

You must have missed:

"It is very likely that later Rybka versions have derived and benefited from Rybka 1.0 beta and hence in the circumstances our view is they should also be considered ...

There are many reasons for that, but it is important to realize that there is a world of difference between studying a program, finding a few tricks you can use, and implementing these techniques in your own program (which everybody agrees is OK) on the one hand, and using somebody else's complete ...

MichaelIsGreat made one relevant point: there is no obvious correlation between playing strength and lines of computer code. If changing one line results in a 100 ELO advantage it is no less an insight than adding 1000 lines to get the same result. That's because random changes of any extent are ...