4 ms·

Which did you see as the conclusive evidence that code was copy-pasted? Section 4 of the article made the point that the Rybka source was missing and the accus

by waqf 15y ago

Which did you see as the conclusive evidence that code was copy-pasted? Section 4 of the article made the point that the Rybka source was missing and the accusers' evidence was decompiled code which they had arranged to look as similar as possible.

waqf 15y ago
Ed Schröder, the initial accuser who recanted, states in summary: "4. It is not possible to state categorically from the available data whether: " 4a. Vas took Fruit source via cut and paste and converted to Rybka; " 4b. Vas kept a copy of Fruit source open on another screen while he wrote Rybka himself; " 4c. Vas absorbed ideas from Fruit (and other open sources) and then coded up Rybka hmself." Source: http://www.top-5000.nl/evidence.htm http://www.top-5000.nl/evidence.htm — worth reading, but just as open to accusations of bias as the other links we've seen.
Someone 15y ago
Yes, section 4 says that, but I do not find that section convincing. IMO, some of its arguments are flawed. For example: "integers are quicker than floating-point numbers" Maybe in this case, but not in general, on all current hardware. Chances are that chess programs use little floating point code. If so, using a few floats here and there can even be faster because it allows the CPU to issue more instructions in parallel. "According to Rajlich, he wrote a utility program (separate from Rybka and not available to users) in the C# language to generate his PSTs. As Fruit is written in C (not C#) this means there is a 100% certainty that Rajlich did not copy the Fruit PST generation code." For low-level chess code (a bit of bit-twiddling, array lookups, arithmetic, but no library calls), I would think that porting C to C# can be an almost 100% copy-paste job. Remarks like these make it hard for me to accept the conclusions as undeniably true. The "but everybody is doing it" argument, on the other hand, I found more convincing.

by waqf 15y ago

waqf 15y ago

Ed Schröder, the initial accuser who recanted, states in summary: "4. It is not possible to state categorically from the available data whether: " 4a. Vas took Fruit source via cut and paste and converted to Rybka; " 4b. Vas kept a copy of Fruit source open on another screen while he wrote Rybka himself; " 4c. Vas absorbed ideas from Fruit (and other open sources) and then coded up Rybka hmself." Source: http://www.top-5000.nl/evidence.htm http://www.top-5000.nl/evidence.htm — worth reading, but just as open to accusations of bias as the other links we've seen.

Someone 15y ago

Yes, section 4 says that, but I do not find that section convincing. IMO, some of its arguments are flawed. For example: "integers are quicker than floating-point numbers" Maybe in this case, but not in general, on all current hardware. Chances are that chess programs use little floating point code. If so, using a few floats here and there can even be faster because it allows the CPU to issue more instructions in parallel. "According to Rajlich, he wrote a utility program (separate from Rybka and not available to users) in the C# language to generate his PSTs. As Fruit is written in C (not C#) this means there is a 100% certainty that Rajlich did not copy the Fruit PST generation code." For low-level chess code (a bit of bit-twiddling, array lookups, arithmetic, but no library calls), I would think that porting C to C# can be an almost 100% copy-paste job. Remarks like these make it hard for me to accept the conclusions as undeniably true. The "but everybody is doing it" argument, on the other hand, I found more convincing.