Good to know.
How does one know when a play is RPO or traditionally called? Can you tell from watching it as a fan?
Not necessarily easy, since something like a standard play-action pass can look similar. But if the quarterback turns his back when handing off / faking the handoff, then it's clearly not an RPO since the quarterback isn't READING anything and the decision has already been made beforehand.
I came across a nice article a couple of days ago that covers recognizing RPOs.
https://985thesportshub.com/listicle/what-in-an-rpo-the-offensive-concept-behind-the-latest-buzzword-around-the-patriots/Here's a snippet, but it continues with more pointers. It's a good article, even if it does mainly concern the Patriots.
it can be tough to distinguish what is or what isn’t an RPO at first watching a play live. It might take a replay or two to figure it out. When trying to do so, there are two key things to look for. If a run play looks like an RPO, watch the receivers. If one or two of them go into a route while everybody else is blocking, and the QB glances to that side of the field before a handoff, that could be a tip it’s an RPO.