[umpjim]

Originally Posted by john5396

BAS's question is not, was this a home run, but when did it become a home run.

First event, hit the top of the fence in fair territory. If the ball bounced back into the field, this would not be a home run, so hitting the top of the fence is not enough to call it a home run. If it bounces away from the field into DBT, then it is a home run after the bounce, when it leaves the playing field.

In BAS's case, the ball bounces parallel to the fence toward the fair pole. Unless the field geometry is weird, this call is either over the fence or over the field on it's way to the fair pole, it is not a home run yet. When the ball hits the fair pole above the top of the fence, it is now a home run and whether it now falls onto field or into DBT fair or foul does not matter.

I didn't see a parallel bounce in the OP but he might have meant that.