Ball deflected over the fence

[kblump]

We’re getting away from the question. The case book situation (8.5.5 situation EJ has for parts. Case book ruling in (). The ball deflects:
a. off top of fence and land in the outfield (gnd ball)
b. Off top of the fence, then F8’s glove then over the fence in fair territory (gnd rule dbl)
c. F8’s glove then over the fence (hr)
d. the top of the fence then goes over the fence in fair territory (hr)

Clearly the fence is not always the ground. If so, d would be a ground rule double. THAT is what I was referring to.

My confusion is based on the ball can go over the fence after hitting the glove (c) or after hitting the fence (d) and it is a home run. However, if it hits both the glove and the fence and then goes over the fence (b), it is not a home run. That makes no sense to me.