At its simplest, a multiple or multiple-bet on horse racing is a bet in which two or more selections in different races are combined into one bet. Multiples may be win-bets, each-way bets, or equally-divided bets – and people like to place these bets because, when they win, they win more than they would have won if they had split their stake into separate single-bets.
The simplest form of a multiple-bet is a win "Double" which is a bet in which both horses must win for the bet to be a winner.
For example, if you placed a £10 win-double on two horses that were both returned even-money, you would win a lot more than if you had placed two £5 singles
If you had placed two £5 singles, each of your bets would have returned £10 - therefore giving you £20 back.
However, a £10 win-double would work like this: £10 at even-money = £20, and this £20 then goes on your second selection at even-money – returning £40. This is double the money you would have had if you'd placed two singles.
However, the obvious downside is that if one horse loses and one horse wins, you get nothing back, rather than the £10 you'd get back if you'd had one single-winner.
Each-Way Multiples
Each-Way Doubles are settled in exactly the same way as each-way singles, in that half of your stake is a win-bet, and the other half is a place-bet.
For example, if you placed a £10 Each-Way Double on two horses priced-up at 5/1 (1/5 the odds for a place), you could win the following.
Two-Winners
£10 Win Double = £360
£10 Place Double = 40
Total Return £400
Two Placed Horses or One-Winner and One-Placed
£10 Place Double = £40
Total Return £40
One-Line Multiple Bets
One-line multiple bets are when you simply place a win, each-way or equally divided bet on two or more selections. Three selections is called a Treble, and any bet with 4 or more selections is called an Accumulator, or simply an Acca.
Combination Multiple Bet
Combination Multiple-Bets are bets that combine selections in various combinations – an example of which is a Yankee. This bet combines 4 selections to make 6 Doubles, 4 Trebles and 1 four fold – making 11-bets.
Some Combination-Multiples also include Singles, an example of which is a Lucky-15. This is basically a Yankee with 4-Singles added to it – so 15-bets.