How to Calculate Baseball Parlay Payouts and MLB Parlay Odds Thinking about betting a baseball parlay, but don’t know if it’s a smart play? Here is a look at how baseball parlays work and the returns you will receive if you win your bet. For starters, baseball parlays are a little different than other parlays. For instance, in basketball and football there are fixed payouts for the number of plays you make. The reason for that is in those sports, the majority of the betting is done on the spread, where the same odds can be found on the favorite and the underdog.