L+2 group
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.
1. Defence against a hane
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.
2. Attacks from within
3. An extra stone
In many of the variations above, Black suffers from shortage of liberties as soon as one of the circled points is filled by White.
4. Weak leg
If Black has a weak leg, White can kill with a rogue ko (in this case, also a two-stage ko).