watching the runner to see if she leaves early

[MNBlue]

You have to watch both, but if I need 'instant' replay to determine if she left early, she didn't.

wadeintothem
I've also found that its easier on you if with body language you convey that you are watching ... Probably every game you will get a complaint that someone left early, mostly done just to keep you as the umpire honest IMO .. but if you are obviously watching its just easier on you .. "How do you know she didnt leave early you werent watching" type convos or complaints.

I've had coaches tell me that when they shout out "Watch the runner leaving early!", they aren't necessarily talking to me. They are attempting to get in the head of the runner and slow her down. Every little bit helps.