Author: Robert Hyatt
Date: 20:45:00 08/23/04
Go up one level in this thread
On August 23, 2004 at 20:29:15, Gerd Isenberg wrote: >On August 23, 2004 at 17:41:38, Matthias Gemuh wrote: > >> >> >>> >>>Such "standard" code like NextMove is IMHO not sufficent to proof El Chinito as >>>Crafty clone. Did i missed something? >>> >>>BTW. Is it legal to disassembly others executables? >>> >> >> >> >>Hi Gerd, >>Is "such standard code like NextMove" also implemented the same way in your >>engine, IsiChess ? Are the Crafty evaluation functions in ElChinito also >>standard and in IsiChess ? Are the reported Crafty bugs in ElChinito also >>standard and present in IsiChess ? > >That IsiChess has a complete other movegen does not proof, that El Chinitos >getMove is a copy of Crafty, even if it is likely, due to the other point with >eval and the 99999 compare. > >I admit that i copied some source code here from CCC via clipboard into my >program, for instance kogge-stone algorithms. The same might be true for others, >and the intention i and others post source-code here is to share it and to get a >feedback, improvements and other ideas. > >Is Crafty's getMove-code really so unique and some code snippets got never >posted here? If i implement some quicksort from some published pseudo code, it >is not unlikely that i get the same assembly, despite other identifiers. That's a poor argument, often tried on me by students. It doesn't fly. A bubblesort or quicksort or heapsort written by two different people might look the same for bubblesort (10 lines of code) but _definitely_ not for quick/heap sort. NextMove() is over 250 lines of code. The chances of two people writing two programs independently, and having them produce the _same_ assembly, is so close to zero that IEEE FP would store it as zero. It really is a vanishingly small probability. So, beyond a doubt, things were copied. How much is unknown at present. But it looks to be a large part of the "chess kernel". IE evaluate, move generation and selection, and who knows what else at present. Numbering the bits backward for the PC. Copying useless bits of code that do nothing except wave a red flag. All of this looks suspect. We'll see whether it has an explanation that is believable or not. > > >>You create the impression that the ElChinito guy is the one doing the right >>thing and Paul H. is rightly to be blamed for his catch-cloner efforts. >>Sorry, but I don't share your strange opinion. > > >For what reason does one disassembly other chess programs? >Was there a beginning suspicion with El Chinito? > >Gerd Probably "curiosity". Same thing that led people to ask me to investigate Le Petite and Voyager a few years back... > >> >>Matthias.
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