I never got too much into the whole "zone" thing for training. The whole 220-age thing is very interesting in how it came about. It actually was never intended to be used the way it is with all of these heart rate monitors.
I had never really even heard of it until recently lol, then it was everywhere.
I tried it for runs - it makes it much more pleasant from a wind standpoint, but trying to run that slow feels wrong, albeit knowing it's a popular technique for those who run a lot. And I do believe you recover quicker.
The baseball thing was just pure curiosity to me - couldn't bring myself to wear a watch while playing to check it, but finally did by putting it on my non throwing arm and covering with a sleeve.