Hate to butt in here......but ROI is also dependent on the cost of picks, right?
If picks are $25 each and a player bets to win $100 per game, his ROI would be different if he bet to win $200, $300, $400 per game, etc.......
When dealing with buying picks and the associated records, it's essential to add in the cost of picks.
Carpe Diem -
Joe D