Who watches the runner?

[waltjp]

If the BU is going out to watch the catch the PU has to watch the tag. You probably won't see both the catch and the tag at the same time and you can't move too far up the line if you're expecting a play at the plate. You can try to listen for the ball hitting the glove and watching the runner or cheat a bit and watch the ball hit the glove and then look at the runner. If you watch for the catch and then look for the tag make sure the runner has clearly left early before honoring an appeal.

Fly ball and tag-up responsibilities should be covered in your pre-game conference with your partner. Don't assume you know who's responsible for what. Talk it over.