What is a middle?
A middle is a bet that profits when the result of a game lands between two different lines offered by two different bookmakers. It is created by dutching handicap or totals markets against each other and is one of the key non-promo strategies available to experienced matched bettors.
Understanding handicap and totals markets
Middles are almost always found in handicap or totals markets, so it helps to understand how these work first.
A handicap market gives one team an imaginary advantage or disadvantage to make both outcomes roughly equal in probability. For example, if Tampa Bay are heavy favourites over Carolina, a bookmaker might offer a line of Tampa Bay -4.5. Tampa Bay need to win by 5 or more for that bet to win. Carolina +4.5 wins if Carolina lose by 4 or less, or win outright.
Alternative handicaps (also called Pick Your Own Line or PYOL) are available at a wide range of handicap values with odds ranging from very short to very long. These are where most middle opportunities are found, because less popular markets are less efficiently priced.
A totals market (also called Over/Under) is a bet on whether a specific stat in the game will finish above or below a set number, for example whether total points scored will be over or under 210.5.
How a middle works
For a middle to exist, two bookmakers must be offering different lines on the same market.
Here is a simple example using AFL. Ladbrokes is offering Collingwood +9.5 or Geelong -9.5 at $2.00 each. Sportsbet is offering Collingwood +8.5 or Geelong -8.5 at $2.00 each. You bet $100 on Collingwood +9.5 at Ladbrokes and $100 on Geelong -8.5 at Sportsbet.
The possible outcomes are:
- Geelong win by 10 or more: you lose the Ladbrokes bet and win the Sportsbet bet. Net result: break even.
- Geelong win by 8 or less, or Collingwood win: you win the Ladbrokes bet and lose the Sportsbet bet. Net result: break even.
- Geelong win by exactly 9: you win both bets. Net profit: $200.
The result landed in the middle of your two lines. With $2 lines on both sides, the worst case is break even and the best case is a double payout.
Negative middles
Not every middle uses $2 lines. Sometimes it is worth accepting a small qualifying loss for the chance of hitting the middle. This is called a negative middle.
How much loss is acceptable depends on the probability of the middle hitting. The lower the chance, the lower the acceptable loss. It also pays to understand the scoring patterns of the sport you are betting on.
In NRL, most teams finish on an even number because a try scores 4 points and a conversion 2. A middle that hits when a team wins by 8 is more valuable than one requiring a win by 7, because 8-point wins are more common.
In NFL, 7-point wins are very common because a touchdown plus conversion scores exactly 7. A middle requiring a win by exactly 7 is highly appealing.
How is the EV of a middle calculated?
The expected value of a middle is calculated by multiplying each possible outcome by its probability and adding the results together. In practice, calculating the probability of the middle hitting can be complex. Our Middles Software handles the EV calculation automatically and is the recommended starting point for finding and assessing middle opportunities.