Re: value of sente; life and death

[Jeremy Thorpe <jthorpe@xxxxxxxxxxxx>]

> Agreed it's not big deal, but you're wrong :) 

oh yea? let's see... 

> Who cares what the "average" value of sente over 100 moves is? The
> variance is huge. If we each get sente a bunch of times when it's worth
> 5 points, but I also get sente once when it's worth 50 points (say,
> because you left a group hanging), I'll win. The fact that the "average
> value of sente" was 8 points isn't going to help you. 

yes, i understand.  however, we are talking about quiet, statically
evaluable positions, which is to say, positions where there are many
nearly equally valuable places around the board to play, so that it
dosen't actually take a different analysis to decide the value of the
position for each color to play.  if there is one single huge place, the
appropriate thing to do is play it out until it's quiet, then evaluate
(and this is clear from the original post).

my point about average values is not that the average value of sente is 
a good estimation for the present value of sente.  let us say that the
value of sente in the first 100 moves is always at least 5.  but your
approximation will most of the time (in quiet positions) give a value of
less than 1.  this is to say that the remaining terms (3rd-4th, 5th-6th)
cannot, in general, be ignored.

> There's a variant of go where white gets to play twice in a row, once
> during the game, whenever he wants, and black takes a handicap to offset
> that advantage. The handicap black needs to make it a fair game is
> probably around 6 stones. In many, many positions, the value of the
next
> move is huge. 

but, the value of the next move is not the same as the value of sente.
sente means the ability to play the next move far away from the current
fight.  The value of sente dosen't actually fluctuate often from move to
move, and when it does, it's not that much.  

> If you drew a graph of the average value of sente over the course of the
> game, it would start low (5-8 points), go up to a big hump during the
> middle game where often the fate of entire groups depends on who has
> sente, then trail off gradually in the endgame. 
>
> > -snip-
>
> I think programs are already well past the 20k life & death level. I'm
> talking about solving general middle game life and death problems of
> normal complexity at the low-kyu level. 

here, i just think you will have a hard time defining the class of
normally complex problems (so i think we'll never know when we're
'there'). otherwise, i have no reason to disagree with your point.

> 
> -David

-jeremy