RTG Problem 53 / Solution

White saves some stones  

If White first, White saves some of his stones with and .

Mistake: all White stones dead  

Although and can capture five Black stones, all White stones are dead after captures the leftmost chain, because capturing the five-stone Black chain at a gives White only one eye.

If at , then the result is essentially a reversion to the previous diagram.

Black first

Black kills all White stones  

If Black plays first, the self-atari of is the only move to kill all White stones. has no other choice than to capture the three Black stones.

Black kills all White stones  

Next, makes a placement, threatening to capture the leftmost White chain via a connect-and-die. We discuss at a to e.

at a  

If proceeds to capture the five Black stones, then captures the leftmost White chain. After , White has only one eye.

at b  

saves the leftmost White chain, but is an atari, allowing to capture the three White stones in a ladder and saving the five-stones Black chain.

at c  

Seeing the failures of at a or b, now tries to increase the number of liberties of the three-stone chain by pressing here. However, after , and reduces White to only one liberty.

at d  

does not work either; after White cannot cut off the two Black stones due to shortage of liberties.

at e  

Against the wedge of , is an adequate answer.