Some auto-fills have a hole at the top edge of the unit that is meant to be an overflow. These are often plugged by the builder. Sometimes there is not a good place to run the overflow water.

Thanks for info..when I look at my autofill I see two holes at the bottom..one is where the "bob" sits and one is, I'm guessing, where the water flows from the pool for the bob to sense..my actual overflow is separate.

It sounds like then that the auto fill usually only acts to fill..any drainage is a result of the overflow. Correct?

Yes. Where I built pools it only rained about 9" a year. Not really enough to warrant an overflow most of the time. Sometimes the pool height just doesn't allow enough slope to get good drainage away from the pool area.

Thanks for the feedback!

That fill does not have a drain.
Some skimmers come with a hole that can be punched out and drain added.