RE: Re[2]: computer-go: perfect play

[Sai To Wang <swang@xxxxxxxxxx>]

This kind of handicap is not the normal one, and in the normal handicap
system, more that 9 stone is not well defined.

Why don´t we just try to find out the komi with no handicap between GoGod
and 9p instead?

The komi between 9p and 1p is about 15 (not sure).

Wang Sai To
[wangsaito@xxxxxxxxxxxxxxxxx]


> -----Mensaje original-----
> De: Heikki Levanto [mailto:heikki@xxxxxxxxxxxxxxxxx]
> Enviado el: miércoles 27 de septiembre de 2000 17:11
> Para: computer-go@xxxxxxxxxxxxxxxxx
> Asunto: Re: Re[2]: computer-go: perfect play
> 
> 
> Roland <goprog@xxxxxxxxxxxxxxxxx> wrote:
> 
> > HL> Funny position, I have 181 non-connected stones, and yet I am
> > HL> unconditionally alive.
> 
> > I think we can lower the limit considerably. All I need is 
> a position
> > where I can assure that I control more than half of the board. So
> > maybe we can place the limit at around 30-40 stones. This would mean
> > we are at most 40 stones from perfect play.
> 
> Yes, of course. But if we require strict mathematical proof 
> of it, we can
> not accept "a limit around 30-40 stones".
> 
> One way to approach a proven limit would be to figure the 
> minimal number of
> stones that will not let white get anything alive. Then fill 
> half board with
> this pattern (make necessary adjustments for the edge), and 
> we ought to get
> to a number that is easy to prove.
> 
> 
> There has been some discussion if white can invade a corner 
> surrounded by
> black stones on the tenth line. I would expect it to be 
> possible to prove
> (exhaustively, if need be) that a 6x6 corner, all empty, 
> surrounded by black
> stones, should be black territory.
> 
>    - - - - - - - -
>   |+ + + + + + X +  (diag. 1. White (O) to invide and live)
>   |+ + + + + + X +  (top left corner of the board)
>   |+ + + + + + X +
>   |+ + + + + + X +
>   |+ + + + + + X +
>   |+ + + + + + X +
>   |X X X X X X X +
>   |+ + + + + + + + 
> 
> The corners give black 4x36 = 144 points of territory. If 
> black passes to
> all white moves outside the corners, white can surround a 
> large cross-shaped
> area of (19x19) - 4x(8x8) = 361-256 = 105 points, a clear 
> victory for black
> with 44 stones.
> 
> Reducing the square to 5x5 empty points gives black 100 
> points, and white
> gets (19x19)-4x(7x7)= 361-196= 165 points. A loss of 65 
> points, with 36
> stones handicap, and assuming a pass on every outside move. 
> It ought to be
> possible to resist the buildup of white territory on the 
> "outside", but if
> that can be proven to be effective enough, I can not say tonight.
> 
> So, Roland, your estimate of 30-40 stones was not badly off. 
> Anyone with a
> lower (provable) limit? 
> 
> - Heikki
> 
> P.S. I am not certain what this says of the strength of 
> GoGod. I would be
> surprised if the number of hadicap stones would be linearily 
> additive to so
> high numbers. 
> 
> 
> -- 
> Heikki Levanto     LSD Levanto Software Development   heikki@xxxxxxxxxxxxxxxxx
>                "In Murphy we Turst"
>