BQM 440

This page I hope will become a place of discussion for players to place go problems which have confused them in some way, even after seeing the solution.
Many of us (beginners, mostly, maybe, maybe not) have encountered go problems that are devoid of discussion. Whether the answer is given or not, some problem sources do not have the goal of discussion in mind. This page is meant to fill the gap. If you've found a problem you don't understand, and isn't explained, discuss it here (or present it here for discussion).
Basically, this differs from other, similar pages in that it is meant to address specific problems that a given player wonders about.

atimholt: This confuses me. I found this problem in a go problem book of mine:

Black to play  

kb: The solution is a case of capture two, recapture one.

Black is alive  

kb: Instead of playing at a to save the stones, it is played to make an eye in combination with .

Black is alive (2)  

When captures, Black can recapture at to form two eyes and live.

kb: Why can't Black just capture the two White stones and live?

Black is alive?  

If White plays 2 at , then Black can play to live.

However, White has a better way to play.

Black dies!  

The vital point has been revealed to be the right 1-2 point, so White should play there. Since this move is sente to capture the three stones (W can push in, starting at a, Black must defend at b - but then White throws in at and Black dies.

atimholt: Thanks for the instantaneous response. I'm a beginner, and will have to look this over a couple times before I really get it.

Wrong  

I didn't see the white throw in at the circle (and I thought white would play 2 at 3)