The L+2 group is an L group with a leg on both sides.
The L+2 group is alive. The corner territory can be reasonably counted as 6 points. We will have a look at: the defense against the hane from either side; how to deflect attacks from within; and the status of this group when White has a stone on either of the marked points.
Against the hane from the short side, one should defend at the 1-2 point. Now there are two sure eyes at the circled points.
See also /Discussion
Answering at the 2-2 point leads to seki - or to ko if that is what Black really wants (see bent four in the corner).
Against the hane from the long side, one should defend at the 2-2 point. Now there are two sure eyes at the circled points.
Suppose the marked stone is added. Now is sente. If
was played at a then the addition of white stones at
and b would not be sente at all.
Black cannot play at a to secure the second eye.
One eye to none, White wins the capturing race.
See also /Discussion.
Here a and b become miai.
Here a and b become miai.
In many of the variations above, Black suffers from shortage of liberties as soon as one of the circled points is filled by White.
If Black has a weak leg, White can kill with a rogue ko.
Black cannot play atari at a because of a shortage of liberties.
In this shape, white can make ko fight with White a.
and
is best response of black.
This is ko fight.
Above shape can be made by black's probing move - , in real games.