The rumors about Strelka beeing a Rybka clone is still alive

[Joachim Wolfram, PhD.]

Thank you.

[Joachim Wolfram, PhD.]

Thank you.

[Joachim Wolfram, PhD.]

How do I use a UCI engine?

[Denis P. Mendoza]

It would be better to have a second look at the code of the UCI version by authorities of this club as well as Vas Rajlich himself to settle this issue once and for all. I dislike false accusations, but considering the evidences again, Strelka needs to face a revalidation.

Hexcomparison software (or just plain hex editors) will show odd similarities in the hexcode of Rybka 1.0 and Strelka 1,6 UCI as reported - 1C4E8-1DD9F hex address in Strelka and 25AC8-2727F hex address in Rybka. I don't know what these means, but I'm sure it is a valid news which we just can't neglect.

[George Tsavdaris]

It would be better to have a second look at the code of the UCI version by authorities of this club as well as Vas Rajlich himself to settle this issue once and for all. I dislike false accusations, but considering the evidences again, Strelka needs to face a revalidation.

Hexcomparison software (or just plain hex editors) will show odd similarities in the hexcode of Rybka 1.0 and Strelka 1,6 UCI as reported - 1C4E8-1DD9F hex address in Strelka and 25AC8-2727F hex address in Rybka. I don't know what these means, but I'm sure it is a valid news which we just can't neglect.

I don't know much about programming but only with some basic logic:

The bytes from 1C4E8-1DD9F hex address in Strelka are 122271-115944 = 6327.
While the bytes from 25AC8-2727F hex address in Rybka are 160383-154312 = 6071.

What kind of similarities do you find in these blocks of bytes? They can't be identical since the size is different....
Are they almost identical? Even almost identical means a very low probability for this to happen by coincidence, since the data sample is very high.

Also if this is true then perhaps these similarities are exist in other programs too. So nothing strange is happening here.
What about Fruit or Glaurung for example? Do they also have such large similarities?

[Michael Sherwin]

It would be better to have a second look at the code of the UCI version by authorities of this club as well as Vas Rajlich himself to settle this issue once and for all. I dislike false accusations, but considering the evidences again, Strelka needs to face a revalidation.

Hexcomparison software (or just plain hex editors) will show odd similarities in the hexcode of Rybka 1.0 and Strelka 1,6 UCI as reported - 1C4E8-1DD9F hex address in Strelka and 25AC8-2727F hex address in Rybka. I don't know what these means, but I'm sure it is a valid news which we just can't neglect.

I don't know much about programming but only with some basic logic:

The bytes from 1C4E8-1DD9F hex address in Strelka are 122271-115944 = 6327.
While the bytes from 25AC8-2727F hex address in Rybka are 160383-154312 = 6071.

What kind of similarities do you find in these blocks of bytes? They can't be identical since the size is different....
Are they almost identical? Even almost identical means a very low probability for this to happen by coincidence, since the data sample is very high.

Also if this is true then perhaps these similarities are exist in other programs too. So nothing strange is happening here.
What about Fruit or Glaurung for example? Do they also have such large similarities?

The slightest change in the code would cause addresses to not align in the two exe's. Large blocks of assembly instructions or data have to be the same or very similar to suggest cloning, no matter how they are offset from each other in the exe's.

[Tord Romstad]

What about Fruit or Glaurung for example? Do they also have such large similarities?

Yes, if you compare the binaries of Fruit and Glaurung 2 - ε/5 with a hex editor, you will almost certainly find one quite long sequence of bytes which is exactly the same in both programs. The reason for this is that my program uses the PolyGlot book format, and therefore needs to contain the same sequence of random numbers that Fruit uses to compute its Zobrist keys.

Tord

[F.Huber]

I don't know much about programming but only with some basic logic:

The bytes from 1C4E8-1DD9F hex address in Strelka are 122271-115944 = 6327.
While the bytes from 25AC8-2727F hex address in Rybka are 160383-154312 = 6071.

Can´t you imagine that it might be just a small typo when writing such hex addresses?
In fact the Rybka address range should be 25AC8-2737F hex, and this makes both blocks the same size.
(BTW, 6328 bytes - that for your ´basic logic´ ... )

What kind of similarities do you find in these blocks of bytes? They can't be identical since the size is different....
Are they almost identical? Even almost identical means a very low probability for this to happen by coincidence, since the data sample is very high.

They are not similar, the are not almost identical - they are absolutely identical!
Coincidence?

Also if this is true then perhaps these similarities are exist in other programs too. So nothing strange is happening here.

Nothing strange happening here?
Well, then search through the billions of programs and files (not just chess engines!) in the whole wide world and try to find exactly that data block of 6328 bytes!

But I can tell you the result already now: you´ll find this data block only in Strelka (the previous WB version and the current UCI version) and in Rybka (in all versions, even more often than once BTW).

So what are the so-called ´experts´ saying now?

[Michael Sherwin]

But, you ignore the possibility of what Tord has written!

[F.Huber]

But, you ignore the possibility of what Tord has written!

The possibility of a 6328 byte block being completely identical??? LOL
You don´t seem to know much about probability ...

And BTW, it can´t have to do anything with opening books, because both engines don´t support it!