Practical Endgame Test 8

Hi this is my first page here, so feel free to erase the odds... First it shows a problem and then the solution. Afterwards I have a question and I hope somebody can give me an answer.

What is the best sequence for Black (assume no captures, and Komi 0)^[1]?

9x9 yose problem  

PracticalEndgameTest8/Discussion

PracticalEndgameTest8/Solution

[1] From Mathematical Go, by Berlekamp and Wolfe.
(BTW, the colors have been reversed. Black has played 23 stones, White 24.)