Re: value of sente; life and death

[Jeremy Thorpe <jthorpe@xxxxxxxxxxxx>]

> Basically if (as in computer go) you're stuck with making a
> simplifying assumption, between assuming:
> 
>  1) that moves after the first and second go in pairs of equal size and
> 
>  2) that moves are evenly spaced,
> 
> I'm not sure which is worse. Clearly neither is true. I'm open to some
> kind of demonstration or argument that (2) is better, but a claim that
> they're evenly spaced won't do, because they're not.

well, i'm not really feeling up to a proof, but here's an idea:  think of
the sum of the rest of the terms (3rd-4th + 5th-6th...) as a random
variable.  well, 1) will give you the minimum possible value, and 3),
which is that 4th=5th, 6th=7th, will give you the maximum (the value of
the 3rd move). 2) will give you like the average of the min and max,
which, i claim is a better estimate than either the min or max.

> And why can you play away from the current fight? Because taking the
> biggest local move is smaller than taking the biggest move on the
> board. That says nothing about the gap between the biggest and the
> next-biggest. And the fact that the biggest move is a lot bigger than
> the next biggest move doesn't necessarily mean that the opponent 
> screwed up - the gote move he just played may have been bigger 
> still. This is how games are won.

i get it.

> 
> > The value of sente dosen't actually fluctuate often from move to
> > move, and when it does, it's not that much.
> 
> What can I say except I couldn't disagree more. 
> 
> If you're still not convinced, I propose an experiment. We arrange a
> game between a reasonably strong player, say me, and a weak player (I
> don't know whether you fit the bill, but that would be the most fun
> :). We'll get a 3rd party, a very strong player, to give us their top
> 10 (or 5) picks for each move. If your assertion is right, the weak
> player will be able pick any of them and be ok, by the middle game he
> should be trailing by at most a few points. If I'm right, he'll be
> crushed.

well, first of all, i'm pretty much aware that in the clear majority of
moves, there's only 1 move to play.  most moves simply aren't 'sente'
moves.

second of all, let's play bitch!  i won't win, but you can't give me 4
stones.  i don't think you have an account on igs, but you can log in and
play anyway...  it's igs.joyjoy.net port 6969.  let me know when you wanna
play.

as far as the test, here's how it should work:  two evenly matched players
play go.  one of them is required to, 20 times in his first 100 moves,
select 5 moves rather than one, and play randomly among these 5.  in
return, he gets 2 handicap stones.  what do you think?  is the test too
weak?

> What do you think?

i think it's 6 minutes into x-mas.

> Let the value of sente be the difference of the 1st and 2nd move, plus
> 1/2 the second (or 1/2 the third, whichever you prefer). If you're
> right about the structure of go, counting the 1-2 difference won't
> matter much. If I'm right, I still get what I want with a (perhaps
> useful) bias term tacked on.

right, okay then, i agree.  and the more terms you actually calculate, the
more accurate the estimate would be.  anyway, i think we both got each
others' points.  alright then...

> I hope I've averted the international crisis.

yea, you have no idea how close my finger was to that little red button.

-jeremy