EndgameProblem41/attempts

Black first  

I'll take the count here as 14 points for reference

White first, in sente  

After this, a Black move at A keeps 9 of the original 14 points. White could play the hane connect left of A, while the point right of A is White's sente afterwards. But it's unclear whether she can do so in sente. Black would then keep 5 of his original points. Let's average it out to 7.

If is sente, it's a 7 point sente.

White first and hane  

If White hane connects on the second line, it might or not be sente against the whole corner. Suppose (which effectively reduces the count to zero there) then later destroys all of the original points in sente and the count is 0. White could even reduce the squared points and make two more for herself. Let's add 4/2 to the count, i.e. -2

White first and descend  

This is surely sente but Black makes 1 point in the corner. Nest the difference between Black A or White B is 5 more points or 2.5 on average.

SO this becomes a -1.5 position, which is slightly worse than the hane connect variation, but more certain of being sente.

Let's assume the former, then the tree becomes, with approximation:

                 6 (8)
                /a\
               14 -2 (7)
                  / \
                -2   5

And the value of the move is about 8