True odds removes the fee a sportsbook builds into its prices from a two-way market so you can see what each side would pay if the book were charging nothing at all.
Parlay combines up to eight legs into one combined price and shows what a given stake pays out if every leg wins.
Book fee adds up every price on a market, two-way or more, and shows how much over 100 percent those prices total, which is the fee the book keeps.
ROI takes units won and units staked from any run of bets and returns the profit as a percentage of what was risked.