Large Avalanche Turn Outward
After , the moves to
are considered the best continuation, although there is some variation possible, especially for
. After this, Black has to choose whether to save or sacrifice his three stones.
Jonathan Cano: I've created a problem for a non-joseki
variation on , at Large Avalanche Turn Outward Problem. The problem begins with
at
.
Nowadays, is considered the joseki move. Black allows White to take his three stones and the corner, making influence in return. The sequence to 5 is the current joseki. Some minor variations are possible: White might forgo the atari at
and play at
directly, while Black might exchange a for White b before playing
. The exchange of a for b used to be the basic joseki, but nowadays it is most often left unplayed, because Black wants to keep the option open of forcing with c rather than a.
Unfortunately I have no commentaries on this ensuing sequence, and I am not strong enough to give them myself. Anyone?
is also a possibility. If White answers at a, the black group is alive (and thus the corner captured), but White b and White c are both sente. It is however more likely that White will immediately counter-attack with
.
Saving the black stones with , rather than sacrificing them with a play at
, used to be joseki.
This used to be a popular joseki around 1950. Nowadays the fact that Black has to play two moves ( and
) to capture the corner is regarded too large a disadvantage.
seemed to improve on a black play at
, allowing Black to take the corner with one move, until the counter-measure of
was discovered.
This is considered good for White because Black still has to take the three stones off the board. So Black's territory is rather small, while White has been able to play on both sides. If Black plays at a, White can create a ko, while if Black does not play
, White plays at b and Black dies outright.
If White plays in the main diagram at
here, White can capture the three stones whatever happens. However, this gives Black too much thickness (note that Black a next makes a ponnuki in sente).
Authors:
- Andre Engels
- (add your name if you make a significant contribution to this page)