Dear Steve,

My question: first off playing , , is gote, so playing because a black play there might be sente seems pointless. Does White not play 2 because he has to play in the area somewhere, rather than tenuki, to prevent Black capturing by playing at 4?

Normally is aji keshi; simply playing leaves White with other options. But in this case a Black play at may threaten to kill, make ko, or at least capture White's three stones and save his two stones. (Start with the hane.)

That being the case, it is not all that clear that Black should not start at . There are better examples of the tesuji.