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Subject: Re: Differences between 0x88 ,10x12 and Bitboards!?

Author: Vincent Diepeveen

Date: 15:14:46 11/19/02

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On November 19, 2002 at 15:08:13, Daniel Clausen wrote:

please mention me 1 bitboard program with a big eval.
  *NONE*.

To me bitboards seems something for people who are no good
programmers, because they can cut'n paste from crafty and
go further with that.

Optimizing gnuchess or gerbil or whatever to something real
fast for your needs is way more difficult of course than
starting with something that's working and written out in
detail.

Usually people also cut'n paste the SEE and qsearch from
crafty then and they have something much better than they
can produce in a lifetime most likely.

That's the only attractive things from bitboards IMHO for
several authors.

And as long as they don't improve the evaluation a lot
it remains like that.

If on the other hand you look to what representation the
good programmers go for, the picture is real clear.

this has nothing to do with religion but with objective speed
differences. My move generator without inline assembly and
with general code for both sides, it is 2 times faster than
crafty at any x86 processor.

That's *objective* measurements.

My SEE is better than the one from crafty, picking up more
than Crafty does in the SEE. Very objectively provable.

The list goes on and on.

Most important thing however IMHO is that the source from
crafty is free. If mine was free, everyone would start with
DIEP and go further from there. I'm 100% sure of it.

We saw this before.

When GNUchess was the strongest freely available source code,
people started with that crap.

I wrote nearly every byte of my move generator. *every* byte.

It took me years to make a fast generator. Not everyone is
that great.

>On November 19, 2002 at 14:04:42, Vincent Diepeveen wrote:
>
>[snip]
>
>>i have posted some months ago and another few months before that loads
>>of examples with regard to evaluation.
>>
>>If you browse some in the search you will find it.
>
>I'm aware of that. But I can't remember that you scientifically proved that
>"bitboards are worse to implement a good eval than 0x88". (or any other board
>representation)
>
>Actually it would be a rather stupid claim to make because there's really no way
>you could prove that. (on the other hand, religions make use of the fact that
>their claims are not provable/disprovable ;)
>
>Just posting some examples where 0x88 is better than <another board
>representation> is not a proof. In fact I'd be surprised if _your_ evaluation
>would be easier/faster to implement with bitboards than with 0x88, as it would
>mainly show that you didn't make use of the advantages of your chosen board
>representation.
>
>While there are clearly inferior board-representations (like storing the board
>internally as a BMP-file ;), generally the art is to find the advantages of the
>chosen representation and make use of them. (that's not only true for chessboard
>representation but for many other things)
>
>Sargon



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