A potentially very profitable situation can occur in sports arbitrage and they are called middles. A middle is an arb where if a match ends with a certain result, you can either win one bet and get the other bet refunded, or win both your bets.
In an asian handicap middle, it occurs when the “+” side is bigger than the “-” side.
For over/under, a middle occurs when the “over” is smaller than the “under” (for instance over 2.5 and under 3.5).
The simplest way of illustrating this is with an asian handicap match. To fully understand this example you need to understand asian handicaps and how different outcomes affect your winnings.
Here’s the example:
$515 for Team1 (-3) 1.90 @ Bookie1
$435 for Team2 (+4) 2.25 @ Bookie2
- If Team1 wins with less than three goals, draws or loses, you win the (+4) bet at Bookie2.
Total Profit = $28.75
- If Team1 wins with more than four goals, you win the (-3) bet at Bookie1.
Total Profit = $28.50
- If Team1 wins with exactly four goals, you win the (-3) bet at Bookie1. Your (+4) bet for Team2 will be refunded at Bookie2.
Total Profit = $463.50
- If Team1 wins with exactly three goals, your (-3) bet for Team1 will be refunded at Bookie1 and you will win your (+4) bet for Team2 at Bookie2.
Total Profit = $543.75
Below is a graphical way of explaining a middle. This time with a basketball game, with the middle hitting (winning both your bets!) at exactly 148 points in the game. This results in a profit of around 100%
As you can see, middles could be quite profitable. If you have ample funds in your bookmaker accounts, you should bet on every middle over 0%. In some cases, it´s even profitable to place negative middles. The profit you could make if the middle hits might be worth the negative arb percentage. There are also middles in other markets.