Xuanxuan Qijing Problem 310 / Solution

Traditional Solution: Kill  

at a and White makes a bulky five. is weak. Instead...

Panda Sensei analysis  

here and ! leads to ko.

Variation  

turn is a mistake. Black lives with .

Another defense  

Go Seigen claims at a is weak and suggests this line: another ko. at .

Panda Sensei refutes  

But above is a mistake. After , Black loses the capturing race. Instead, at , or a leads to ko.

Takagi 1  

Takagi Shoichi solution 1: ko (This is correct)

Takagi 2  

Takagi Shoichi solution 2: ko (partly wrong. at is correct, leading to ko)

Takagi 3  

Takagi Shoichi solution 3: ko (wrong. at kills.)

Cont. 1  

(Note the similarities to the Go Seigen ko)

All lead to ko  

Panda Sensei shows many ways to make ko, at a to e, with the marked stones added. Variations are complex....