Many bettors don’t know that due to overround multiplication, accumulators are usually not a good bet! Find out why you should usually avoid placing accumulators, and possible solutions.
- Accumulators may initially seem attractive, as they may offer the chance to win a lot of money, from a relatively smaller amount gambled.
- Accumulators allow you to combine multiple bets (usually 4 or more), and potentially win big IF ALL your selections win.
- However, the potential of big winnings from accumulators isn’t all that it seems.
- Let us explain everything you could you want to know about accumulators, including the problems and possible remedies, in this definitive guide.
How do accumulators work?
Accumulators consist of multiple bets, and vitally ALL the bets need to win for you to make a profit (and get your stake back). If your first bet wins, BOTH the winnings and the stake combine, and become the stake for the second bet etc.
- Purists may claim only 4 bets and above are technically called accumulators.
- 4 bet accumulator = a fourfold. 5 bet accumulator = fivefold. 6 bet accumulator = a sixfold.
- However, we are happy to call the following accumulators too: doubles (2 bet accumulator), and trebles (3 bet accumulator). This is because doubles and trebles mathematically work in exactly the same way as any other accumulators.
Example of how a winning 4 fold accumulator, produces massively increased winnings compared to 4 single bets
We have used fractional odds in the above example as this is the default with most UK bookmakers. However, we suggest switching to decimal odds for quicker maths.
- Let’s say you have £60 to bet in total, on 4 bets at odds of 3/1, 4/1, 5/1, and 6/1.
If you bet £15 on each of this outcomes separately, you stand to make the following profit on each bet (and get your £15 stake back):- 3/1 : £45
- 4/1: £60
- 5/1: £75
- 6/1: £90
- If all the selections won you would get £270 in profit (and get your £60 of stakes back).
- However, if you decided to put the same total amount of money in an fourfold accumulator (£60) on the same odds at your favourite bookmaker, you stand to win £50,400 (and get your original £60 stake back).
- Your £60 stake is placed on the 3/1 bet – if it wins £240 is placed on the 4/1 bet – if it wins £1,200 is placed on the 5/1 bet – if it wins £7,200 is placed on the 6/1 bet. If that wins you stand to win £50,400 (and get your original £60 stake back).
- Each time, the profit and stake from the previous bet, becomes the new stake for the following bet.
Before, you get too excited remember if even one leg of your accumulator fails your bet loses. In the case of singles, you make a profit for every one of your winning singles. Moreover, as you will see at the end of this article, due to overround multiplication accumulators aren’t usually a good bet.
What are Full Cover Bets?

Full Cover Bets in horse racing betting, are bets consisting of all possible doubles, trebles, and fourfold and above (as appropriate) accumulators across a given number of selections.
As long as at least two of your horses win, you will get something back (although this does not necessarily mean you will profit overall).
You can also chose to cover all the singles too. Then, you will get something back if just one horse wins (again this does not necessarily mean you will profit overall).
The cost of Full Cover Bets
The more separate bets being placed as part of your Full Cover Bets, the higher your stake. A £1 Trixie, will cost you £4 in stakes (as 4 separate £1 bets are placed). A £1 Patent will cost you £7 in stakes (as 7 separate £1 bets are placed).
Types of Full Cover Bets
Trixie / Patent
- Choose three horses you think will win (from three different horse races).
- Your bet consists of four separate bets (three doubles, and one treble).
- If you wish to include the 3 singles too (Trixie, plus 3 singles), this is a Patent.
Yankee / Lucky 15
- This time you pick four horses to win, from four different races.
- Your bet consists of six doubles, four trebles, and one fourfold accumulator.
- That’s 11 separate bets.
- If you wish to include the 4 singles too (Yankee, plus 4 singles), this is a Lucky 15 (as there are 15 separate bets).
Canadian / Lucky 31
- Make five selections from five different races to win.
- That’s 26 separate bets (10 doubles, 10 trebles, 5 fourfold accumulators, and one fivefold accumulator).
- If you wish to include the 5 singles too (Canadian, plus 5 singles), this is a Lucky 31.
Heinz / Lucky 63
- Choose six horses from six different races to win.
- That’s 57 separate bets – i.e. 15 doubles, 20 trebles, 15 fourfold accumulators, 6 fivefold accumulators, and 1 sixfold accumulator.
- If you wish to include the 6 singles too (Heinz, plus 6 singles), this is a Lucky 63.
Super Heinz / Super Heinz, plus 7 singles
- Pick 7 selections from 7 different races.
- That’s 120 separate bets – 21 doubles, 35 trebles, 35 fourfold accumulators, 21 fivefold accumulators, 7 sixfold accumulators, and one seven fold accumulator.
- If you wish to include the 7 singles too (Super Heinz, plus 7 singles), that’s 127 separate bets.
What are Forecasts & Tricasts?

Forecast betting involves picking both the winner and runner up, in a single horse race. Your picks have to finish in your specified order.
Forecast betting (as well as the others below) might be useful if the favourite (the horse usually most likely to finish 1st) has a low price.
Computer software works out the winnings, using the starting prices of the horses.
Want to name the horse to finish exactly 1st and 2nd (how about 3rd as well)?
Forecast betting (Straight)
- In horse racing betting, if you would like to predict which horse will win, and which will will be the runner-up (i.e. finish second), you can place a Forecast (known as Exacta or Perfecta in the USA).
- If you place a Forecast, if you get the winner right your profit AND original stake becomes the new stake for the runner-up.
- If you get the runner-up right as well, you will get a return.
Tricast betting (Straight)
- If you would like to predict which horses will finish 1st, 2nd, and 3rd (naming the horses that will finish in each position), you can place a Tricast (known as Trifecta in the USA).
- Again, the winnings on the 1st horse (including stake), becomes the new stake on the 2nd horse, and the winnings on the 2nd horse (including stake) becomes the new stake on the 3rd horse.
Want to predict all the horses that will finish in the top 2 (or top 3) in any order?
Reverse Forecast betting
- You could also place a Reverse Forecast (predicting the top 2 horses, but the order does not matter).
- The stake is double that of a Straight Forecast, as it is the equivalent of placing 2 Straight Forecasts.
Reverse Tricast betting
- Similarly, there are also Reverse Tricasts, which involves predicting the top 3 horses, but the order does not matter.
- The stake is six times that of Straight Tricasts, as it is the equivalent of placing 6 Straight Tricasts.
- Forecast betting involves picking both the winner and runner up, in a single horse race.
- Your picks have to finish in your specified order.
Forecast betting might be useful if the favourite (the horse usually most likely to finish 1st) has a low price.
Important: Why should accumulators usually be avoided?

We would suggest looking at the section about overrounds in our definitive guide to Betting Odds. In summary, bookmakers will usually build in a profit margin on the markets they offer. This is why there is an overround. In the case of accumulators, overrounds multiply – which is a big problem if you are looking for value.
Let’s look at an example
- Let’s say you place a double, with both bets having an overround of 12%.
- To calculate the combined overround: [(1.12 x 1.12) multiplied by 100] minus 100 = 25.44% overround
Bookmakers would love you to place this double, rather than 2 single bets. As an double the total overround is more than double the individual overrounds.
- Let’s say you place a 4 selection accumulator, and all four bets have a 12% overround.
- To calculate the combined overround: [(1.12 x 1.12 x 1.12 x 1.12) multiplied by 100] minus 100 = 57.35% overround
- As an accumulator the total overround is a lot more than quadruple the individual overrounds.
As you can see the more selections you have, the worse it gets for the bettor.
- Finally, to see if you have understood let’s look at a more complicated example.
- Let’s say you place a 6 selection accumulator and the bets have a 6%, 8%, 9%, 10%, 12%, and 13% overround.
- To calculate the combined overround: [(1.06 x 1.08 x 1.09 x 1.10 x 1.12 x 1.13) multiplied by 100] minus 100 = A massive 73.72% overround
Is there any solution to mitigate this problem?
You will need a bookmaker to give you a bonus on your accumulator to compensate as much as possible for the problem.
In fact some bookmakers do mitigate this issue by offering bonuses on certain accumulators on certain sports (you must check all T&Cs that apply). For example, they may and a certain percentage to your winnings, which may increase the more legs in your accumulator. Others may offer accumulator insurance, e.g. money back as a free bet if exactly one leg of your accumulator fails.
Where a bookmaker does not offer such bonuses, we would strongly recommend staying away from accumulators – but if you must place an acca, keep your selections to the minimum!