Source:
Problem diagram.
White plays.
Ikuro Ishigure, Ishi Press
Solution follows
(or click here to download SGF)
Correct.
White 1 must first address the pushing battle in the center.
The Black extension at 2 is natural, but then White can then
defend the top with 3.
Black 4 is the proper play to support the center group.
But with White's strong center group, White can take the big point on the left side with 5.
Black variation.
Invading with Black 2 is not good.
With White 3 and 5 and the all important White 1, White splits Black into 2 weak groups.
Too slow.
After White 1, Black can push against the still weak center group with 2.
White must respond to the pushes.
Through Black 10, White's center wall is useless given Black's right side formation.
Also, Black has gained great strength over the left side.
White failure.
White 1 is a mistake in direction.
After 2, Black has forcing moves starting with A in reserve,
after which White's marked stone is in some danger.
Hits: 842