An accumulator is a popular form of multiple bet or, in other words, a single bet on multiple selections, in different races, which is successful if, and only if, all selections win. The term ‘accumulator’ is typically reserved for bets involving four or more selections; bets involving two or three selections operate on the same principal, but are usually known as ‘doubles’ or ‘trebles’.
Regardless of the number of selections, the idea is that the winnings from the first selection, including the original stake, roll over onto the second selection and so on, until the bet is complete or one of the selections loses. An accumulator is, by nature, an ‘all or nothing’ bet, but it is possible to combine selections in such a way that a return is due if, say, four, five or six win. Six selections, for example, could be combined in 15 four-fold accumulators, six five-fold accumulators and one six-fold accumulator. Of course, each accumulator requires its own individual stake, so the viability of such an approach, ecomonically, depends on the odds available for each selection and your attitude to risk.
The history of horse racing is awash with stories of punters who have won vast sums of money – hundreds of thousands, or even millions, of pounds – for a small initial outlay with accumulators of one form or another. However, an accumulator, of any kind, involves betting at multiple odds, so udnerstand what you are attempting before parting with your hard-earned cash.