Re: computer-go: unmake move?

[Ray Easton <ray.easton@xxxxxxxx>]

Don Dailey wrote:

> Yes,  my evaluation  is very  simple, almost  all of it  is calculated
> before the search begins.   I do have a  specific move ordering I  use
> but it  doesn't involve a full   blown sort.  The  program does little
> serious work (and it probably shows  because it doesn't play very well
> either!)
>
> I  think this is   a  good argument  in favor  of  copying  state.  My
> program, because  it does  very little, should   show state copying at
> it's very worst  if it's  in fact a    bad idea.

How so?  It seems to me that the very opposite is true -- because your program
"does little serious work", there is little state to maintain.  A program with
a more sophisticated evaluation function is likely to maintain much more
state.  And it seems to me that the *more* state that is maintained, the
bigger the performance penalty for copying rather than writing the code in
such a fashion as to facilitate rapid undos.

--

ray

    -- je suis marxiste, tendance groucho