On 13-mei-08, at 15:44, Álvaro Begué wrote:
On Tue, May 13, 2008 at 2:28 PM, Mark Boon
<[EMAIL PROTECTED]> wrote:
On 13-mei-08, at 15:08, Jason House wrote:
The range of the random number is reduced by one after each failed
lookup.
Shuffled data has no impact on future use of the array of empty
points.
OK, I understand now why a point at the end (or beginning) is a
little less
likely to be picked. Although I still have doubts whether that
will lead to
a noticable bias, I'll try to think about it.
I don't care much about it being noticeable. This thread is about
putting bots on CGOS that use a reproducible algorithm, to help people
detect bugs in their implementations. As part of specifying what these
bots do, we should all pick the next move in a playout using the same
criteria. If we agree to use uniform distribution among empty
non-eyeish points, that's what should be implemented.
Indeed it seems I misunderstood. I thought the general algorithm
needed to be the same, not necessarily the exact implementation. Why
not publish some pseudo-code with the exact statements then? Seems a
bit less prone to errors then by talking about it.
I would imagine moving an illegal point towards the end and only
start
including it when the other 'legal' moves run out can lead to
terrible bias
however because they may not remain illegal for very long and
actually
become important points to play. A ko-point is probably the most
extreme
example of that.
I don't think you understood the algorithm. The eyeish point is
removed from the lottery only for picking this particular move, not
for the rest of the playout.
Yes, again I misunderstood. So you do another random lookup each time
you hit an illegal point? That could turn out very expensive,
especially by the end of the game.
Anyway, I don't bother to order the empty-point-list or scramble
them in any
way prior to the game. So the first point is the 1-1 point and the
last is
the 19-19 point (or whatever boardsize you're playing) so I have
no qualms
about those moves being a little less likely to be played. Or even
a lot
less. I think it would actually be beneficial.
Reproducibility was the point, not strength of the bot.
I'd say, share the source if that's the objective. I doubt you'll get
real reproducibility any other way.
If this asymmetry really bothers you, you could very easily fix
this by
wrapping the search around. There's no asymmetry in a circle.
That doesn't fix anything.
Why not? The whole argument is about a bias against points towards
the end. In a circular list there is no 'end'.
Mark
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