caranthir: I disagree with synco, this does not revert to the same problem as 8/20 because of presence of K19 stone. In the answer line of 9/20, K19 is necessary for preventing defender from escaping out.
Farkas: 8 and 9 are undoubtedly somewhat similar, but still two different problems.
synco: Too many white stones I believe.
No first move on the edge works.
And if black cuts first then this becomes the same problem as the previous one (8/20) and there the object is that other player has to live!!!
d4rkm4tter: In 8/20 the opponent misplays by trying to capture the 4 stones. 9/20 shows there is an actual sequence to kill the entire group.
Your move has been added.