Enforcement puzzle

[mbyron]

Originally Posted by kdf5

In 5., that is totally wrong. What kind of play was occurring at the time of B's IBB? Was it a running play? Was it a loose ball play? You better say running play because it wasn't a loose ball play. Where is a running play enforced from? It's enforced from the end of the run, right? Where was the end of the run? It was where B fumbled. That's why you throw a bean bag. You would enforce B's IBB from the bean bag.

I think you had this right in an earlier post. While B is in possession, they are by definition the offense. The spot of their foul is behind the basic spot/end of the run (presumably), so under ABO the penalty would be enforced from the spot of the foul.