Parlay (gambling) – Wikipedia

A parlay, accumulator, combo wager or multi is a single bet that links together two or more individual wagers and can be determined by all of those wagers winning together. The benefit of this parlay is that there are far higher payoffs than putting each individual wager separately, since the problem of hitting all of them is higher. If any of those bets in the parlay shed, the whole parlay loses. If some of those plays at the parlay ties, or”pushes”, the parlay reverts to a lower amount of teams together with the odds decreasing accordingly.
Parlay bets are paid out at odds higher than the typical single game wager, but still below the”true” chances. For instance, a common 2-team NFL parlay based completely on the spread generally has a payout of 2.6:1 if the two picks are right. [citation needed] In reality, however, if one assumes that every single match bet is a coin flip and would be expected to pay out in 1:1, the genuine payout should rather be 3:1, a substantial gap.
The house creates a 20-31% gain on spread parlays, when compared with a 7% gain on individualized sports bets. [2]
An alternate way to do a parlay would be to bet on at least two favorites simply winning up. In order to calculate the payout of the parlay, one must multiply out the payout for all 3 matches. For example, if 3 teams are all +385 favorites, a successful parlay on all 3 teams winning would pay out in a ratio of roughly 1/1. This is since (385/485)^3 is roughly 50 percent