Small avalanche - trick play
In the small avalanche joseki, (instead of a) is a trick play that may be played when the ladder at b is good for Black. The refutation for White can be hard to find however.
is natural to prevent the ladder, but after
, it seems that White has a problem. The tesuji at
saves the day.
With the moves up to , Black can cut off
, but White takes the corner and manages to escape with
as well.
If White tries to avoid being sealed in by playing at
, Black will connect under at
, and White's horrible shape quickly becomes apparent.
With , White has fallen for the trick play. With the moves up to
, Black seals white into the corner while cutting off
. White can push through at a, but b is atari, forcing White to capture, after which Black can finish his wall with a move at c.
As white descended she has an extra liberty and can push through and capture the stone on the 2nd line in sente, which is a big improvement over the previous diagram. I (Uberdude) think this is playable for white as she gets sente and there is still some aji on the outside: activating the marked cutting stone and the peep at a are things to look forward to.
See also: