The main problem with sports betting is people don't know how to manage money. What I do is take 2 percent of my bankroll, then that is my base unit size. Then when looking at a game I will decide on a 5 point scale how much i like that game. Then I will take that number and multiple it by the 2 percent and thats how much I'm wagering on a game. This way if I have a bad day I wouldn't break the bank. In terms of futures they vary from .25 units to 1 unit. I go with the low risk high reward thinking, and futures shouldn't break the bank. If you lose a future it shouldn't be a big deal.