Not something I've taken out time to check but, I must agree with the stakes for reward definition. Its almost ethical from a common sense perspective that, you've got to have something of value to lose by a means of your inaccurate prediction. If you ain't having anything at stake, then it's not gambling.

Okay, How about just making predictions without expecting any monetary reward but, just the cheer for beibg right or annoyance when you get it wrong. Those too could be some reward, lol... its even funny to me but, gambling has to come with a stake on both sides.