Richard Malcolm: There is Ko with the sequence B2C2D2A4C1A2
guile: There is a stronger defense with A17 instead of D18, but anyway it is still Ko because of the strong leg with E17 : well done !!!
I removed the surrounding to avoid this and preserve the spirit of the serie.
I think the old version of this tsumego should be added and complete the serie (thx to you) to provide 3 similar positions.
Thx a lot for your review.
There is a stronger defense with A17 instead of D18, but anyway it is still Ko because of the strong leg with E17 : well done !!! I removed the surrounding to avoid this and preserve the spirit of the serie. I think the old version of this tsumego should be added and complete the serie (thx to you) to provide 3 similar positions. Thx a lot for your review.