I have found out that if you win a lot of strikes during the first 24 hours that the machines pay better. If you do not win a lot during the first 24 hours then they do not pay so good. During a full moon they do not seem to pay out as good either.

I have also noticed that when you have $700 in a machine and about 25 strikes in your tray a tourist will come along and say "Wow! You sure are lucky."