I have had a couple of ten inning FP games as I recall - both games competitive with evenly matched teams. As I recall, both games were decided by errors. Those are the kind of games that are fun to call, and you hate to see one team have to lose.
My longest time game that I remember was a HS JV FP game, start time 4:00 pm, we walked off the field at 7:20 pm. Here's the kicker - it was a five inning run rule! Neither team had a pitcher and they couldn't hit, field, or throw.....other than that, it was a good ball game.
I was BU. My PU partner's strike zone had gotten so big as the game went on, if the ball didn't bounce on the way to the plate, it was pretty much a strike - even then we had numerous walks.
The game was played in early March when darkness hits about 6:00 pm. As the sun started going down, a school maintenance guy drove over in his golf cart and started turning on the field lights - I wanted to go strangle him!
I recall going to the bottom of the fifth inninng with the home team down by about 8 runs. Thankfully (?) they scored 18 runs in the inninng by a variety of errors, walks, and maybe one or two legitimate hits.
What a nightmare that game was.....