What is the exact formula for computing how much John Doe handicapper has really returned to $100 bettors?

I keep seeing touts touted as 'returning X number of dollars to $100 players.'  No matter what formula I apply to their won/loss record, I can't come up with the same total winnings for a $100 player as they do. I've tried using both 10% vig and 5% vig in my formulas, but it's still off. (5% is a lot closer to what the touts advertise than the standard sports book vig of 10%, but they don't tell you what vig they're actually using). What is the correct, exact formula to use, step by step? 
With regard to the seeming controversy as to WHO pays the vig, I'm currently of the belief that the winners pay all of the rake cause they only get back approx. 90% of what they put up. The losers just lose 100% of what they put up. 

Some/an example(s) please? Which include win-loss-push record, amount won, unit bet and commission rate..