From: William Harold Newman <william.newman@xxxxxxxxxxxxxxxxx>
I'm familiar with minimaxing, and probably the original poster is
also. Alas, once you break the game into subgames, where tenuki is
allowed, you can no longer determine a useful minimax value locally,
because globally optimal play includes local tenuki, and decisions
about where and when you tenuki are affected by other subgames. Your
other proposals for a integer score fail in this problem for analogous
reasons.
Sorry. I hadn't realized you were referring to local subgames only, in
which case all I can say is that you're right.