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Uri Blass wrote:

Matthias Gemuh wrote:

Bill Rogers wrote:Well Alex as far as I can remember someone here decompiled both Rybka 1 and Fruit and found only a very small amount of code duplicated in both and that was not enough to claim Rybka is a clone. You should read a lot more history in this site.
Bill

Then that "someone" is either unable to decompile or unable to read decompiled code.
OTOH, the guy who by decompilation deciphered the node count obfuscation of Rybka1 proved at source code level that Rybka1 was basically Fruit21.
If you chose not to look at his lengthy evidence, blame yourself.

Matthias.

It is also possible that the "someone" has a different definition of
"very small" relative to your definition.

The question here if the facts that are proved mean that Rybka1 is basically fruit.

There is no doubts that ideas from fruit are used in rybka but the target of GPL is to protect code and not ideas.

Uri

Alexander Schmidt wrote:

Uri Blass wrote:There is no doubts that ideas from fruit are used in rybka but the target of GPL is to protect code and not ideas.

Uri

Taking ideas don't result in a similar UCI output. But I respect your opinion. I would wish the people would be sceptical with clone accusation also for other engines

Best wishes,
Alex

bob wrote:BTW, this c1/e1/g1 king shelter stuff in pawn hash is not from Fruit. at least not originally. This has been in Crafty for 10-12 years. It was first done in the 9.x versions somewhere. So apparently ideas get copied from everywhere.

Eelco de Groot wrote:

bob wrote:BTW, this c1/e1/g1 king shelter stuff in pawn hash is not from Fruit. at least not originally. This has been in Crafty for 10-12 years. It was first done in the 9.x versions somewhere. So apparently ideas get copied from everywhere.

If this was copied from somewhere I just have to take Zach's word for it but I don't think it was copied from Fruit, I can't remember any such generalization from the King shelter calculation in Fruit or Toga. Maybe I missed something or misunderstood code but I do not see it in eval.cpp. King Safety in Fruit is rather simple but sufficient. So I think Fabien should not be associated with code theft from Crafty 9

Regards, Eelco

bob wrote:

Uri Blass wrote:

Matthias Gemuh wrote:

Bill Rogers wrote:Well Alex as far as I can remember someone here decompiled both Rybka 1 and Fruit and found only a very small amount of code duplicated in both and that was not enough to claim Rybka is a clone. You should read a lot more history in this site.
Bill

Then that "someone" is either unable to decompile or unable to read decompiled code.
OTOH, the guy who by decompilation deciphered the node count obfuscation of Rybka1 proved at source code level that Rybka1 was basically Fruit21.
If you chose not to look at his lengthy evidence, blame yourself.

Matthias.

It is also possible that the "someone" has a different definition of
"very small" relative to your definition.

The question here if the facts that are proved mean that Rybka1 is basically fruit.

There is no doubts that ideas from fruit are used in rybka but the target of GPL is to protect code and not ideas.

Uri

Nowhere in our discussion was the term "very small" used. Unless you use "copy of fruit with very small changes added."

Uri Blass wrote:

bob wrote:

Uri Blass wrote:

Matthias Gemuh wrote:

Bill Rogers wrote:Well Alex as far as I can remember someone here decompiled both Rybka 1 and Fruit and found only a very small amount of code duplicated in both and that was not enough to claim Rybka is a clone. You should read a lot more history in this site.
Bill

Then that "someone" is either unable to decompile or unable to read decompiled code.
OTOH, the guy who by decompilation deciphered the node count obfuscation of Rybka1 proved at source code level that Rybka1 was basically Fruit21.
If you chose not to look at his lengthy evidence, blame yourself.

Matthias.

It is also possible that the "someone" has a different definition of
"very small" relative to your definition.

The question here if the facts that are proved mean that Rybka1 is basically fruit.

There is no doubts that ideas from fruit are used in rybka but the target of GPL is to protect code and not ideas.

Uri

Nowhere in our discussion was the term "very small" used. Unless you use "copy of fruit with very small changes added."

very small is taken from the blue letters of Bill Rogers that you can see
also in the quoted text in the beginning of this post.

Nasir_Shaheen wrote:

bob wrote:

Spock wrote:For the record then - are you accusing Vas of being a liar when he says Rybka is 100% original source code ?

If he says Rybka 1 has no fruit code whatsoever, then I would certainly say that. If he simply says "Rybka has no fruit code" that is a different statement, since I have not personally looked at any disassembled Rybka 2 or 3 code at all.

But rest assured, Rybka 1 does have code from Fruit. Unless you somehow believe that two different people can write identical code completely independently, for a program as complex as chess. Students don't write identical code for assignments that are 100-200 lines long. Or even for assignments 50 lines long. Statistically, I suppose it _could_ happen. Just as I could flip 1,000,000 heads in a row. But it is not very likely at all.

Hi Hyatt , Some young programmer Zach Wegner has given some points in rybka forum to show that rybka 1 is based on fruit , the points he given are following :

" Rybka's piece square tables are generated from the same code as Fruit's (same KnightRank, etc. constants, but different KnightRankOpening weights)
Rybka's pawn evaluation is virtually identical to Fruit's (different weights again, candidate pawns and backward pawns have a very slightly different formulation)
Rybka's passed pawn evaluation is virtually identical to Fruit's (same bonuses using the quad array {0...,26,77,154,256}, only difference is weights and free_passer split into 3 separate bonuses and based on rank)
Rybka's piece evaluation is virtually identical to Fruit's (different weights only)
Rybka's king shelter evaluation is virtually identical to Fruit's (different weights again, king square generalized to C1, E1, or G1 to store in the pawn table, and a slightly different formula for shelter_file()/storm_file())
Rybka's king safety evaluation is virtually identical to Fruit's (different weights for KingAttackWeight, KingAttackUnit)
Rybka's "pattern" evaluation is virtually identical to Fruit's (different weights, TrappedBishop is not halved for A6/H6).

I have confirmed all of this from reverse engineering Rybka 1, though anyone can see for themselves by looking at *****. Rybka's entire evaluation is basically an optimized and tuned bitboard translation of Fruit's, with Fruit's material evaluation replaced by the infamous lookup table. EVERY single evaluation term in Rybka 1, except for the material imbalance table, appears in Fruit. If everyone wants to consider that "original", then computer chess is really dead.
And this is only the evaluation. There are many more similarities.. "
..........................................................................................................

As i don't have any back ground in Programming so I want your openion on these points . Are these points valid ?
If YES , then there is not doubt that Vas has violated the GPL.

Also in this case reverese engineering the current Rybka is absolutely legal.

Bill Rogers wrote: The Coding looks identical to Crafty with only different weights.
The biggest question is WHO COPIED WHO?

Eelco de Groot wrote:

Bill Rogers wrote: The Coding looks identical to Crafty with only different weights.
The biggest question is WHO COPIED WHO?

Bill the guy was obviously just feeding the flames. I am sure there is indentical looking code in Fruit and Crafty that Robert can claim his own but this part does not seem to be in Fruit. I could not find it as I could not find any separate pawn hash in Fruit also ...

Thanks,
Eelco