Problem diagram.
Black plays.

Source:
   From a tsumego collection.

Analysis:
   Myron Souris

Can a pro make a mistake on a kyu level tsumego problem?!
You decide.

Solution follows    (or click here to download SGF)

A mistake?
Black 1 and 3 is the "official" solution, but only gives White 4 as the defense! After Black's throw-in at 7, White dies with only 1 eye.

See the SGF for other lines for this entire problem.

White refutation?
But the unmentioned White 4 seems to only give Black a ko. White's throw-in at 6 is the key. With 9, Black only has a ko that White takes 1st.

Another White refutation?
Even an earlier White 2 seems to lead to a ko. Through 6, White has a ko.

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