I've already finished the 5th inning but threw a no-hitter in RTTS yesterday and got almost 16k in XP. I know it's currently double XP but that's still 7k a RTTS game...which takes about 20 minutes so in less than 2 hours, one can theoretically be at/over the daily XP limit.
Seems like a pretty low number for folks that can only play a few days a week but are able to play a lot during those days.