Beginner Exercise 144 / Attempts

White to play.  

Zephi: This one seems a bit complicated, but I can see at least two possibilities. Focusing on only the two marked stones, white needs B to keep them from escaping, but can't play there without being immediately captured, so I think white would have to first set up a ko at point A. After this, I think that B and C are miai for capturing, though white would need some good ko threats to make B work. Here's how I think both cases would look:

Black blocks the ko  

Black looks pretty dead if he just connects to avoid the ko.

Black allows the ko  

In this case, black takes first in the ko, so white needs to have some really good ko threats to make this work.

White plays b first.  

Again, Black takes first, and white needs a very good ko threat. ( seems like it would only cause black to fill in the ko in which case, playing at c is no longer an option for white.)

Well, if this isn't the solution, I hope it's at least on the right track.

Shortage of liberties.  

unkx80: Sorry, but Zephi's solution is correct. In your diagram, can connect, but cannot play at a without putting himself into self-atari.