Kyu Exercise 104 / Solution

Standard tesuji  

fills.

Bill: - is a standard wringer, as Quacki showed. Then after LukeNine45's tesuji, is a standard tesuji in reply.

White captures 4 stones  

Then if , - captures four stones.

White wins the fight  

If instead, wins the fight. Because of damezumari, Black cannot play at a.

Here is what I see (7 just left of 3)  

So where did I screw up? :)