[Careyy]

I think there are two potential perspectives:

1) The ball itself establishes the neutral zone and after 4th down and an inc pass, that neutral zone is unchanged. B (now A) has gained nothing in terms of the neutral zone. This also avoids the safety in the case where rotation around the leading point of the ball would cause the length of the ball would intersect the goal line. Plus in effect the ball was 49.9 yards from the goalline for B, the rotation has move it to 50, B loses yardage.

2) If the leading edge it what "A" has gained, then "B" would gain the ball length, unless the ball is rotated arounfd that leading edge. The issue in this case would be the ball close to the goal line and associated safety.

So if we look at it from the perspective of the established neutral zone being what "A" has gained vs the leading edge of the ball, we go with #1.

I look at is as neutral zone establishment, and see the logic in avoiding the safety. I don't know Canadian rules, so if you do start from no closer than the 1, then the ball rotation safety could be avoided, and using the leading edge and rotation works, without that start from the one it wouldn't.

So if we rotate B can be seen to lose the ball length vs your argument that they gain without rotation.

As I see it the ball has a length and there are in effect two lines of scrimmage, one for A and one for B, replacing the ball back in the same position keeps both of these lines the same, rotation moves them.