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Subject: Re: definition of clones: Danchess an Crafty

Author: Robert Hyatt

Date: 12:10:53 02/15/04

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On February 15, 2004 at 14:45:36, Dann Corbit wrote:

>On February 15, 2004 at 14:36:56, Robert Hyatt wrote:
>
>>On February 15, 2004 at 13:41:42, Uri Blass wrote:
>>
>>>On February 15, 2004 at 13:29:16, Dann Corbit wrote:
>>>
>>>>On February 15, 2004 at 13:24:54, Uri Blass wrote:
>>>>
>>>>>I understood from the winboard forum that Bob considers DanChess as a crafty
>>>>>clone and the question is what is the definition of a clone.
>>>>>
>>>>>I remember from slater's post in this forum that if most of the code is
>>>>>different you cannot win in court by complaining that it is a clone.
>>>>>
>>>>>I understood from Dann's post that only 30% of the code of DanChess is
>>>>>similiar(that does not mean the same as Crafty).
>>>>>
>>>>>Dann Corbit posted in the winboard forum the SEE function of Danchess that is
>>>>>similiar to Crafty.
>>>>>I wonder if it is really the main reason that Bob considers Danchess as a clone
>>>>>or only one of the reasons.
>>>>
>>>>There are more reasons that that one routine.  Several routines are similar.  He
>>>>also used some ideas from eval that are found only in crafty.  For instance, he
>>>>had a stonewall detection.  The only other program I ever saw with stonewall
>>>>detection was crafty.
>>>>
>>>>There is no standard for:
>>>>"This is a clone"
>>>>or
>>>>"This is not a clone"
>>>
>>>I believe that there are some standards.
>>>
>>>Suppose that a strong program with the same similiarity to Crafty becomes
>>>commercial and the author does not hide the similiarity and even share the
>>>similiar code that it has to crafty.
>>>
>>>I believe based on your descreption that if Hyatt go to court and sue the
>>>programmer then it is clear that the court is going to decide against him.
>>>
>>>>
>>>>It is clear to me that if you use ideas from someone else and they challenge you
>>>>as to cloning, then you may have a big problem to sort it out.
>>>
>>>I use alphabeta
>>>I use null move
>>>
>>>What other people can do against me?
>>
>>
>>This is called a "strawman" argument.  Nobody is claiming that or arguing from
>>that perspective.  The point here is _source code_.  Do you think it ok to
>>borrow a chapter from a book, change the main character's name, and sell it as
>>your own?  Copyright law does _not_ say it is ok.  Nor is it ok to take
>>thousands of lines of code from Crafty, change a few variable names, and then
>>call it a new program.
>>
>>I think it is great if someone looks at the source, reads the comments, gets
>>some ideas they like and implement them.  Much of the _original_ Crafty design
>>came right from the "Chess Skill in Man and Machine" book chapter on chess 4.0.
>>But I copied _no_ source since none was given.  Ideas are ok to copy.  But _not_
>>thousands of lines of source.
>>
>>That is the point here, it keeps getting lost in all the minutia...
>>
>>
>>
>>
>>
>>>
>>>
>>>
>>>  Therefore, if
>>>>someone has an idea you want to use, I think the only wise course is to send an
>>>>email and ask if you can use the idea.
>>>
>>>I think that it is absurd.
>>
>>I think both of you are absurd here, because you are arguing a point of view
>>that nobody holds.  If you can't see the difference between copying an idea and
>>copying an actual source program, perhaps there is nothing more to say?
>
>I think that it is an honest difference of opinion.  I also do see where you are
>coming from.  I also understand your frustration at many of the blatant crafty
>rip-offs.  It makes perfect sense to me for you to put your foot down and holler
>"ENOUGH IS ENOUGH!"
>
>But I think Daniel Shawul may be bearing the brunt of the mistakes of others.
>In any case, we all agree that it was a terrible oversight not to mention the
>use of crafty ideas in his program.  He is doing a complete rewrite to 0x88 (and
>in fact has already accomplished it).  So I think it would be nice to let
>bygones be bygones and forget the whole matter.
>
>I still have great respect for all of the parties involved and I think it would
>be nice to have everyone forgive all of the others.

I don't have anything to "forgive".  I simply answered a question with my
opinion.  I don't hold anything against anyone here.  I simply don't like
calling the current "DanChess" a "unique chess program".   Any newcomer is going
to have to tolerate a certain amount of microscopic examination, for obvious
reasons...  Too many past examples to just say "OK"..  Otherwise our chess
events become meaningless...




>
>
>>>Do I need to ask people if I am allowed to use null move pruning?
>>>What in case that I think independtly about an idea that other people use in
>>>their soutce code and I did not read the source code?
>>>
>>>
>>>Uri



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