Mechanics question
 

Fed, two umpires. R2, one out. Long fly ball to left center. F8 runs to the wall, leaps and catches the ball with his waist at the top of the wall and his upper body over the other side. R2 stands on 2nd and runs to third as F8 extricates himself from the wall.

Where is the BU at the time of the pitch and where do both go afterward?

Assuming R2 is at 2b (FED is so confusing with the R's), BU is in C at TOP. PU stays at the plate and BU stays in the deep C (inner edge of infield grass) unless there is going to be a play at 3B, which I doubt, in this situation. If there is going to be play BU takes the play at 3B.

Why you ask, seems easy?

On this play...

PU....is staying at home plate.

BU....is starting in the C slot. Once the ball is hit, you have the catch/no catch on the fly ball AND you have the tag-up of R2. You want to get into a position where you can see both.

I think some mechanics have PU taking any play at third, even with R2 only. Most however, give this to BU (and even when the "official" mechanics have PU take it, crews often ignore this).

All have BU starting in C and responsible for the catch and the tagup at second.