Forecast bets can be placed in doubles and trebles just like any single selection in a race. The return from a winning race runs onto the other selections as in an ordinary bet.

If you find this data useful, you may enjoy our full article on **Forecast Doubles & Trebles** betting.

The table below details the total number of bets to be placed for a given number of races selected.

SFC-D = Straight Forecast Doubles

RFC-D = Reverse Forecast Doubles

SFC-T = Straight Forecast Trebles

RFC-T = Reverse Forecast Trebles

Races | SFC-D | RFC-D | SFC-T | RFC-T |
---|---|---|---|---|

1 | - | - | - | - |

2 | 1 | 4 | - | - |

3 | 3 | 12 | 1 | 8 |

4 | 6 | 24 | 4 | 32 |

5 | 10 | 40 | 10 | 80 |

6 | 15 | 60 | 20 | 160 |

7 | 21 | 84 | 35 | 280 |

8 | 28 | 112 | 56 | 448 |

9 | 36 | 144 | 84 | 672 |

10 | 45 | 180 | 120 | 960 |

11 | 55 | 220 | 165 | 1320 |

12 | 66 | 264 | 220 | 1760 |

13 | 78 | 312 | 286 | 2288 |

14 | 91 | 364 | 364 | 2912 |

15 | 105 | 420 | 455 | 3640 |

16 | 120 | 480 | 560 | 4480 |

17 | 136 | 544 | 680 | 5440 |

18 | 153 | 612 | 816 | 6528 |

19 | 171 | 684 | 969 | 7752 |

20 | 190 | 760 | 1140 | 9120 |

22 | 231 | 924 | 1540 | 12320 |

24 | 276 | 1104 | 2024 | 16192 |

26 | 325 | 1300 | 2600 | 20800 |

28 | 378 | 1512 | 3276 | 26208 |

30 | 435 | 1740 | 4060 | 32480 |

32 | 496 | 1984 | 4960 | 39680 |

34 | 561 | 2244 | 5984 | 47872 |

36 | 630 | 2520 | 7140 | 57120 |

38 | 703 | 2812 | 8436 | 67488 |

40 | 780 | 3120 | 9880 | 79040 |

42 | 861 | 3444 | 11480 | 91840 |

44 | 946 | 3784 | 13244 | 105952 |

46 | 1035 | 4140 | 15180 | 121440 |

48 | 1128 | 4512 | 17296 | 138368 |

50 | 1225 | 4900 | 19600 | 156800 |

If you find this data useful, you may enjoy our full article on **Forecast Doubles & Trebles** betting.

## What is straight forecast vs reverse forecast?

When placing a forecast bet in the UK, there are two main types of forecast bets to choose from – straight forecast and reverse forecast.

A **straight forecast** is where you predict the exact finishing order of the first two horses. So if you bet on horse A to finish 1st and horse B to finish 2nd in that exact order, that is a straight forecast.

With a **reverse forecast**, you are predicting the first two finishing horses but the order doesn’t matter. If you bet on horse A and horse B to finish 1st and 2nd in either order, that is a reverse forecast.

The key difference is that a straight forecast requires you to correctly predict the exact finishing positions, while a reverse forecast is a bit more flexible since the order doesn’t matter.

Both a straight forecast and a reverse forecast can be combined in doubles and trebles to cover more outcomes and more races.

## How do you calculate straight forecast doubles?

To work out how many straight forecast doubles are in a given number of races, use this simple formula:

(**number of races** multiplied by **number of races -1**) divided by two

**Examples**:

Four Races = (4 x 3)/2 = 12/2 = 6 Straight Forecast Doubles

Eight Races = (8 x 7)/2 = 56/2 = 28 Straight Forecast Doubles

Ten Races = (10 x 9)/2 = 90/2 = 45 Straight Forecast Doubles

## How do you calculate reverse forecast doubles?

Reverse forecast doubles work in much the same way as a straight forecast double above, only this time you are covering many more options. Instead of each double being a single bet, now there are four possible permutations.

To work out how many reverse forecast doubles are in a given number of races, use the same calculation for a straight forecast double above but then multiply the result by four (to cover the extra permutations), use this simple formula:

((**number of races** multiplied by **number of races -1**) divided by two), multiplied by four

**Examples**:

Four Races = ((4 x 3)/2)*4 = (12/2)*4 = 24 Straight Forecast Doubles

Eight Races = ((8 x 7)/2)*4 = (56/2)*4 = 112 Straight Forecast Doubles

Ten Races = ((10 x 9)/2)*4 = (90/2)*4 = 180 Straight Forecast Doubles

A simple way to do this calculation, without referencing the straight forecast doubles is to use this formula for a direct result:

(**number of races** multiplied by **number of races -1**) multiplied by two

We’ve detailed the basics on this page, for further details and information, check out out article on **Forecast Doubles & Trebles** betting.

## How many straight forecast doubles in one race?

Zero, it’s not possible to do a forecast double with only one race. A straight forecast on this one race is possible and advisable. Stick with your original selection, don’t go adding others just to make a bet.

## How many straight forecast doubles in two races?

When placing a straight forecast double bet on just two races, selecting only two horses in each, there is only one possible double forecast. For example, if you choose horses A and B to finish 1st and 2nd in Race 1, and horses C and D to finish 1st and 2nd in Race 2, this gives just one potential straight forecast double of A-B and C-D.

Even though there are multiple permutations of the finishing order within each race, the straight forecast requires predicting the exact finishing positions. So with two selections in each of the two races, there is precisely one straight forecast double bet.

## How many straight forecast doubles in three races?

When placing a straight forecast double bet on 3 races, selecting 2 horses in each race, there are 3 possible double outcomes:

- Race 1 & 2: Horses A & B in Race 1, and Horses C & D in Race 2
- Race 1 & 3: Horses A & B in Race 1, and Horses E & F in Race 3
- Race 2 & 3: Horses C & D in Race 2, and Horses E & F in Race 3

So with 2 selections in each of 3 races, there are 3 potential straight forecast doubles, by pairing each race with the other two.

## How many straight forecast doubles in four races?

When placing a straight forecast double bet on 4 races, selecting 2 horses in each race, there are 6 possible double outcomes:

- Race 1 & 2: Horses A & B in Race 1, and Horses C & D in Race 2
- Race 1 & 3: Horses A & B in Race 1, and Horses E & F in Race 3
- Race 1 & 4: Horses A & B in Race 1, and Horses G & H in Race 4
- Race 2 & 3: Horses C & D in Race 2, and Horses E & F in Race 3
- Race 2 & 4: Horses C & D in Race 2, and Horses G & H in Race 4
- Race 3 & 4: Horses E & F in Race 3, and Horses G & H in Race 4

With 2 selections in each of the 4 races, there are 6 potential straight forecast doubles, by pairing each race with the other 3 races.

## How many straight forecast doubles in five races?

When placing a straight forecast double bet on 5 races, selecting 2 horses in each race, there are 10 possible double outcomes:

- Race 1 & 2: Horses A & B in Race 1, and Horses C & D in Race 2
- Race 1 & 3: Horses A & B in Race 1, and Horses E & F in Race 3
- Race 1 & 4: Horses A & B in Race 1, and Horses G & H in Race 4
- Race 1 & 5: Horses A & B in Race 1, and Horses I & J in Race 5
- Race 2 & 3: Horses C & D in Race 2, and Horses E & F in Race 3
- Race 2 & 4: Horses C & D in Race 2, and Horses G & H in Race 4
- Race 2 & 5: Horses C & D in Race 2, and Horses I & J in Race 5
- Race 3 & 4: Horses E & F in Race 3, and Horses G & H in Race 4
- Race 3 & 5: Horses E & F in Race 3, and Horses I & J in Race 5
- Race 4 & 5: Horses G & H in Race 4, and Horses I & J in Race 5

With 2 selections in each of the 5 races, there are 10 potential straight forecast doubles.

## How many straight forecast doubles in six races?

When placing a straight forecast double bet on 6 races, selecting 2 horses in each race, there are 15 possible double outcomes:

- Race 1 & 2: Horses A & B in Race 1, and Horses C & D in Race 2
- Race 1 & 3: Horses A & B in Race 1, and Horses E & F in Race 3
- Race 1 & 4: Horses A & B in Race 1, and Horses G & H in Race 4
- Race 1 & 5: Horses A & B in Race 1, and Horses I & J in Race 5
- Race 1 & 6: Horses A & B in Race 1, and Horses K & L in Race 6
- Race 2 & 3: Horses C & D in Race 2, and Horses E & F in Race 3
- Race 2 & 4: Horses C & D in Race 2, and Horses G & H in Race 4
- Race 2 & 5: Horses C & D in Race 2, and Horses I & J in Race 5
- Race 2 & 6: Horses C & D in Race 2, and Horses K & L in Race 6
- Race 3 & 4: Horses E & F in Race 3, and Horses G & H in Race 4
- Race 3 & 5: Horses E & F in Race 3, and Horses I & J in Race 5
- Race 3 & 6: Horses E & F in Race 3, and Horses K & L in Race 6
- Race 4 & 5: Horses G & H in Race 4, and Horses I & J in Race 5
- Race 4 & 6: Horses G & H in Race 4, and Horses K & L in Race 6
- Race 5 & 6: Horses I & J in Race 5, and Horses K & L in Race 6

With 2 selections in each of the 6 races, there are 15 potential straight forecast doubles.

## How many straight forecast doubles in seven races?

When placing a straight forecast double bet on 7 races, selecting 2 horses in each race, there are 21 potential straight forecast doubles.

## How many straight forecast doubles in eight races?

When placing a straight forecast double bet on 8 races, selecting 2 horses in each race, there are 28 potential straight forecast doubles.

## How many straight forecast doubles in nine races?

When placing a straight forecast double bet on 9 races, selecting 2 horses in each race, there are 36 potential straight forecast doubles.

## How many straight forecast doubles in ten races?

When placing a straight forecast double bet on 10 races, selecting 2 horses in each race, there are 45 potential straight forecast doubles.

## How many straight forecast doubles in eleven races?

When placing a straight forecast double bet on 11 races, selecting 2 horses in each race, there are 55 potential straight forecast doubles.

## How many straight forecast doubles in twelve races?

When placing a straight forecast double bet on 12 races, selecting 2 horses in each race, there are 66 potential straight forecast doubles.

## How many straight forecast doubles in thirteen races?

When placing a straight forecast double bet on 13 races, selecting 2 horses in each race, there are 78 potential straight forecast doubles.

## How many straight forecast doubles in fourteen races?

When placing a straight forecast double bet on 14 races, selecting 2 horses in each race, there are 91 potential straight forecast doubles.

## How many straight forecast doubles in fifteen races?

When placing a straight forecast double bet on 15 races, selecting 2 horses in each race, there are 105 potential straight forecast doubles.

## How many straight forecast doubles in sixteen races?

When placing a straight forecast double bet on 16 races, selecting 2 horses in each race, there are 120 potential straight forecast doubles.

## How many straight forecast doubles in seventeen races?

When placing a straight forecast double bet on 17 races, selecting 2 horses in each race, there are 136 potential straight forecast doubles.

## How many straight forecast doubles in eighteen races?

When placing a straight forecast double bet on 18 races, selecting 2 horses in each race, there are 153 potential straight forecast doubles.

## How many straight forecast doubles in nineteen races?

When placing a straight forecast double bet on 19 races, selecting 2 horses in each race, there are 171 potential straight forecast doubles.

## How many straight forecast doubles in twenty races?

When placing a straight forecast double bet on 20 races, selecting 2 horses in each race, there are 190 potential straight forecast doubles.

## How many straight forecast doubles in twenty-two races?

When placing a straight forecast double bet on 22 races, selecting 2 horses in each race, there are 231 potential straight forecast doubles.

## How many straight forecast doubles in twenty-four races?

When placing a straight forecast double bet on 24 races, selecting 2 horses in each race, there are 276 potential straight forecast doubles.

## How many straight forecast doubles in twenty-six races?

When placing a straight forecast double bet on 26 races, selecting 2 horses in each race, there are 325 potential straight forecast doubles.

## How many straight forecast doubles in twenty-eight races?

When placing a straight forecast double bet on 28 races, selecting 2 horses in each race, there are 378 potential straight forecast doubles.

## How many straight forecast doubles in thirty races?

When placing a straight forecast double bet on 30 races, selecting 2 horses in each race, there are 435 potential straight forecast doubles.

## How many straight forecast doubles in thirty-two races?

When placing a straight forecast double bet on 32 races, selecting 2 horses in each race, there are 496 potential straight forecast doubles.

## How many straight forecast doubles in thirty-four races?

When placing a straight forecast double bet on 34 races, selecting 2 horses in each race, there are 561 potential straight forecast doubles.

## How many straight forecast doubles in thirty-six races?

When placing a straight forecast double bet on 36 races, selecting 2 horses in each race, there are 630 potential straight forecast doubles.

## How many straight forecast doubles in thirty-eight races?

When placing a straight forecast double bet on 38 races, selecting 2 horses in each race, there are 703 potential straight forecast doubles.

## How many straight forecast doubles in forty races?

When placing a straight forecast double bet on 40 races, selecting 2 horses in each race, there are 780 potential straight forecast doubles.

## How many straight forecast doubles in forty-two races?

When placing a straight forecast double bet on 42 races, selecting 2 horses in each race, there are 861 potential straight forecast doubles.

## How many straight forecast doubles in forty-four races?

When placing a straight forecast double bet on 44 races, selecting 2 horses in each race, there are 946 potential straight forecast doubles.

## How many straight forecast doubles in forty-six races?

When placing a straight forecast double bet on 46 races, selecting 2 horses in each race, there are 1035 potential straight forecast doubles.

## How many straight forecast doubles in forty-eight races?

When placing a straight forecast double bet on 48 races, selecting 2 horses in each race, there are 1128 potential straight forecast doubles.

## How many straight forecast doubles in fifty races?

When placing a straight forecast double bet on 50 races, selecting 2 horses in each race, there are 1225 potential straight forecast doubles.