Combat Series 5, The Nose
Like a lot of these initial techniques the Nose is another way to restrict liberties to attack stones. The key though is that the Nose only works when one direction is blocked already and the other is favourable. Otherwise your opponent will just contact play out until safe. Perhaps with a heavy shape and little points but alive all the same and what we really want to do is to kill. Here is the book (Tesuji by James Davies) suggestion. The key here is that the two white stones have 3 liberties as does the three black stones below. Whoever plays first has a good chance to kill the other and separate. White would need to play an earlier Tesuji and A. If Black plays first and connects at A as a defensive measure then those two stones could conceivably spread up and threaten the corner three black stones. Now the Tesuji is to play to the left of the two white stones (the so called nose) and as a contact play that reduces whites liberties to two this needs dealing with. It is two purpose
