BQM 462

Invasion  

Fernobob: Playing as white, I was recently faced with the following invasion. I tried because it looked like an unreasonable invasion, but after moves 1 to 8, it seems to be alive. I've looked around for other moves that might work, but can't find any. I always thought that this was a fairly secure shape and feel that it shouldn't have lived. Is there any way to kill it, or at least end up with a slightly better outcome?

Andy: Not recommended, but if you really have to kill, white play at seems to do the job.

Point of symmetry  

Bill: is on a point of symmetry. Now, as Andy Pierce says, Black cannot live inside. Note that is necessary to give White another liberty if Black cuts on this side.

White wins the semeai  

Bill: Note that and give White an extra liberty, which enables White to win the semeai. Note also that Black gets something in exchange for losing the invaders.