I'd say on average there are 2 possible game points per game.
The math works out that way. Figure a team gets to possible, they
then has a 50/50 shot of ending it right there. So half the games
end at the first possible game point. Then half continue on, and
then 50% of those games end at the 2nd possible game point. Then
half continue on, etc. If you carry this forward you end up at
around 1.99 - then the numbers get too small to be meaningful
to compute and you'd be at the maximum anyhow which is the second
part.
As far as the maximum, I believe the most there could be in a
Spec 7 game would be 11. And that would be 10 possible game points
where the team with possible loses, then the 11th point would
be a "this is game point" situation where both teams
would be at possible game point and whoever wins that point takes
the game. If everyone just took turns winning points (ie. 2 beats
1, 3 beats 2, etc.) then you'd only have 9 possible game points.
But if the 1 runs to possible, then loses to the 8 who goes to
possible, then the rest "fill in" around them with the
team at possible losing every time....you'd end up with the 11.
