This section contains general information about another strategy that gives players an advantage over bookmakers – *bookmaker middles*.

A middle is something in between a surebet and a regular bet (sometimes even a valuebet).

The similarity to surebets lies in that it is also a combination of two opposite bets placed on the same event. The difference from a surebet is that a middle must always consist of two such bets that can both win when a certain outcome occurs. In addition, a middle does not guarantee a profit for any outcome.

Let us take a look at two opposite overlapping bets on a certain event: a match total over 4.5 and a match total under 5.5. If the match total is 4 or less, only the second bet wins and the first one loses. If the match total is 6 or more, the first bet wins and the second loses. No matter the outcome, the loss from one of the bets is compensated by the profit from the other one, thus bringing overall losses to a minimum. However, a total of exactly 5 is what makes looking for middles worth the while – both bets win! It is called *hitting a middle* (when both bets in a middle win) and a set of outcomes in which it occurs are called *middle outcomes*.

As a rule, your *profit* is 60%+ of the total bet amount and your *loss* does not exceed 15% (within an average bookmaker’s margin). Therefore, a middle is a set of bets on an event that minimizes possible losses and lets you win a lot more than you bet. This makes middles very similar to regular bets – the player may lose a certain percent of the total bet amount in order to hit a middle and increase the bet amount by a bonus amount (multiplied by a certain odd) that the player is willing to risk.

The ratio of the possible profit when hitting the middle to the possible loss when missing it is called *the middle odds*.

`K = Profit / Loss`

To find a middle, you need to find two bets meeting the following criteria:

- no matter the outcome, at leat one of the bets wins
- the bets have an overlapping range of outcomes that cause both bets to win (or at least cause one bet to win partially and the other one to be returned)
- the value of the odds lets you distribute the bet amount in a way that allows the player to lose the same small amount for any outcome outside the middle.

To locate such a set of bets, you need to collect the lines from as many bookmakers as possible and go through a maximum of bet combinations to check if they meet the conditions above. Not only is this hard, meticulous and calculation-intensive work, but the search must be as fast as possible since you want to work with the most up-to-date data.

Middles can be differentiated by the following characteristics:

- markets involved
- bet behavior in a middle
- middle estimation

The main types of middles by **markets involved** are Total – Total and Handicap – Handicap. For example:

`Over(3.5) – Under(4.5)`

`AH1(-0.5) - AH2(+1.5)`

*Equivalent bets* allow you to make more complex middles:

`AH1 (+1.5) – 2`

`1X – X2`

`1X – AH2 (+0.5)`

etc.

The following types of middles can be distinguished by **bet behavior in a middle**:

- both bets win: AH1 (+0.5) – AH2 (+0.5); both bets win in case of a draw
- only one bet wins, the other bet is fully returned: AH1 (0) – AH2 (+0.5); in case of a draw, the first bet is returned and the second one wins
- both bets partially win: AH1 (+0.25) – AH2 (+0.25); in case of a draw, both bets win 50%.
- one bet partially wins and the other one is returned in full: AH1 (0) – AH2 (+0.25); in case of a draw, the first bet is returned completely, while only a half of the other bet is returned. The other half wins.

There are also middle-surebets with guaranteed profit. Loss for them is negative, i.e. they always win. The profit is around a couple of percent in any case, and 50% or more when a middle is hit.

If we look at middles as bets that make the player risk a certain amount to win with certain odds, we will probably want to ask: are the odds worth risking your money? To answer this question, we first need to assess the probability of hitting a middle. If the multiplication of this probability by the middle odds is higher than 1, this middle is worth trying. Such middles are called overestimated middles. This makes playing with middles similar to valuebetting. To assess the probability of hitting a middle, you have to sum up the probabilities of each outcome comprising the middle and subtract 100% from the resulting amount. Underestimated middles occur quite often even within the same bookmaker. The underestimation value is nearly equal to the bookmaker’s margin. It means that playing all the available middles is like betting blindly. This is a losing strategy from a long-term perspective. Playing overestimated middles, on the other hand, is a winning strategy in the long run. That is why middles require a very careful estimation of probability of hitting them.

During an automated search, our system assesses the probability of hitting middles and filters out the obviously underestimated ones. This process is identical to that for valuebets.

Middles combine the advantages and drawbacks of surebets and valuebets.

Pros

- The player risks a little to win a lot.
- Regular middles occur a lot more often than surebets.
- Betting on overestimated middles gives you an advantage over the bookmaker.
- Betting on surebet-middles guarantees profit in any case and considerable profit when hitting a middle.
- Playing middles raises less suspicion with bookmarkers than surebetting because of the more natural behavior of players.

Cons

- No guaranteed winning when playing on regular middles.
- Overestimated middles are not that frequent.
- Prior to placing your bets, you have to check all middle outcomes for validity and compliance with limits.

It is harder to identify a player who is using middles than to identify a surebetter, for instance. However, you should be aware of the same potential problems as when betting on surebets. In the long run, you will be winning only when betting on overestimated middles, since regular middles give no guarantee of consistent winning. It is also worth stressing that with automatic middle search, the player saves himself from routine calculations. However, the machine can make mistakes and all the obtained data should be carefully checked before placing a bet.