Re: [Bug-gnubg] Re: gnubg bug?

[Christian Anthon]

This is quite odd. My local linux version doesn't seem to have this
problem. Anybody with their own builds having this problem?

Christian.

On Tue, Aug 4, 2009 at 10:56 PM, Christopher Yep<address@hidden> wrote:
> It looks like you are correct; the problem is due to pruning.
>
> Using a recent build (0.90-mingw 20090721):
>
> With pruning turned off, gnubg gets the correct backgammon values for both
> moves (21/17 19/18: 8.5%, 20/16 19/18: 9.3%) at all plies (0-ply, 1-ply,
> ..., 7-ply).
>
> With pruning turned on, gnubg gets the correct backgammon values at 0-ply,
> 1-ply, and 5-ply, but gets incorrect backgammon values (21/17 19/18: 16.6%
> BGs, 20/16 19/18: 12.4% BGs) at 2-ply, 3-ply, 4-ply, 6-ply, and 7-ply.  It's
> strange that gnubg gets it correct at 5-ply, but not 6-ply or 7-ply, but
> note that the game always ends by the end of the 5th ply (the top player is
> guaranteed to bear off in 3 rolls).
>
> How much slower is gnubg when pruning is turned off in racing positions?
>
> Chris
>
> At 03:44 PM 8/4/2009, Michael Petch wrote:
>>
>> Howdy Team,
>>
>> I find that a lot of the fringe cases (with such incorrect results) like
>> this usually occur on the race evaluator near end games. If this is a
>> result
>> of pruning, maybe we might consider not pruning when the race evaluator is
>> being used?
>>
>> On 04/08/09 1:23 PM, "Michael Petch" <address@hidden> wrote:
>>
>> > This is cross-posted to bgonline:
>> >
>> > We call it "Gnu Math"?
>> >
>> > On a serious note this seems like a prime example of neurel net pruning
>> > at
>> > its worst. I don't have GnuBG handy but what do you get by turning
>> > "Pruning"
>> > off? I recently had a discussion with Neil Kaz (I think it was Neil -
>> > but if
>> > it wasn't, it was another world class player) - about the settings I use
>> > in
>> > Gnubg. Besides using a Huge Filter I spend the extra time and turn the
>> > pruning off. I've seen this type of thign before.
>> >
>> > Has anyone tried the position without pruning? Sorry I can't test it
>> > from
>> > here.
>> >
>> >
>> > On 04/08/09 12:45 PM, "address@hidden" <address@hidden> wrote:
>> >
>> >> http://www.bgonline.org/forums/webbbs_config.pl?noframes;read=45761
>> >>
>> >
>
>
>
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