[bob jenkins]

Originally Posted by David Emerling

I meant to clarify that this is OBR.

Thanks Bob, that's what I recall - but I wasn't sure.

What if it was the same play, only with runners at 1st and 3rd and, at the time of the interference, R1 had advanced and was standing on 2nd? Can he remain there?

Yes.

And, if it was bases loaded and both R1 and R2 had advanced, they'd both have to go back.