2007/2/6, Nick Wedd <[EMAIL PROTECTED]>:
I have put a short report on the event at
http://www.weddslist.com/kgs/past/23/index.html

"In round 3, GNU, playing against MoGoBot13, played the marked move in
the diagram. This is a blunder – it can only live its group by making
a second eye at L7 (it had earlier missed another opportunity to make
this eye, connecting unnecessarily at N6 instead). MoGoBot13 answered
correctly at L7, killing the group and winning the game."

This is all wrong.

1. Connecting at N6 is necessary. If N6 is played at L7, black plays
K3 and white loses capturing race at the bottom because of shortage of
liberties. It should be understood as a backfilling move to play N3.

2. When white played K6 (marked move), white group didn't need any defense.

In the game, after K2-N3-L7, white can live by playing N1 (capturing 3
stones). To kill, black is forced to play M2, then white plays K3,
threatening to capture either K2 or K4.

If black plays K3-N3-L7 to protect this weakness, N1-M2-K2 makes an
eye at the bottom.

If black simply plays L7, white lives with K2. If black plays
elsewhere to destroy an eye potential at the bottom (J2 for example),
white plays L7 and lives.

Note: above analysis was done using GNU Go. In other words, GNU Go
understood all of these.

3. GNU's true blunder is 4 moves later. After L7, it should have
played N1 after all! From GNU Go's trace log, it seems that it didn't
see K3 as a move to attack the whole group. It considered K3-N1 and
declared a tactical win. This really shows weaknesses of the program,
but understanding of eyes is not one of them.

--
Seo Sanghyeon
_______________________________________________
computer-go mailing list
[email protected]
http://www.computer-go.org/mailman/listinfo/computer-go/

Reply via email to