Gokyo Shumyo, Section 6, Problem 21 / Solution

Solution  

This connection tesuji is the same one found in Beginner Exercise 70. Black has only four ways to block White's connection, marked a, b, c and d.

Response a  

After , a and b become miai.

Response a  

here is probably the strongest resistance in this problem. After , the four Black stones (containing and ) is caught in a connect-and-die via a double ko.

Response b  

This is the analogue of the first variation of response a. If at a, then the same works.

Response c  

Connect-and-die after .

Response d  

Same as previous response.