Parlay Bets
A parlay or accumulator is a single bet that links together two or more individual wagers and is dependent on all of those wagers winning together. The benefit of the parlay is that there are much higher payoffs than placing each individual bet separately since the difficulty of hitting it is much higher. If any of the bets in the parlay loses, the entire parlay loses. If any of the plays in the parlay ties, or "pushes", the parlay reverts to a lower number of teams with the odds reducing accordingly.

Odds and payout
Parlay bets are paid out at odds higher than the typical single game bet, but still below the "true" odds. For instance, a common 2-team NFL parlay generally has a payout of 2.6:1 if both picks are correct.In reality, however, if one assumes that each single game bet is a coin flip and would be expected to pay out at 1:1, the true payout should instead be 3:1, a substantial difference

Example 1

 Winning example

You wager $1,000 on Arsenal/Manchester United to draw, Chelsea to win and Liverpool to win. You win $6,072 as you correctly predicted all three results.

The calculation is: $1,000 × 3.2 × 1.7 × 1.3 = $7,072, less the stake of $1,000.

Losing example

You wager $1,000 on Manchester United to win, Chelsea to win and Liverpool to win. You lose the wager as Manchester United did not win.