In addition to straight bets, each way bets and accumulators, there are some quite complex bets you can use when betting on the horses.
These are based on permutations and are designed so that you do not need to be 100% accurate in your predictions: you can win if only some of your predictions turn out to be correct. Naturally the closer you come to getting everything right, the more money you win.
These types of bets are called a full cover bets. They consist of multiple selections in a number of different events and are made up of every possible combination of double accumulators, treble accumulators, four fold accumulators etc up to the total number of selections made. All the bets have identical stakes. Some of these multiple bets include single bets and some do not.
Popular examples of these kinds of bets are the Lucky 15 and Yankee bets. With these bets you make four selections on four different events. With the Yankee to bet is composed of all doubles, trebles and one fourfold accumulator and the Lucky 15is composed of similar double, triple and fourfold but also includes singles.
Calculating the outcome of these bets can be quite complicated, and we will show how it is done with a Lucky 15. Assume that you have correctly predicted four winners. They have come in at 5/1, 13/2, 8/1 and 7/1.
We must revert to the mathematics of basic factors. These are terms which when multiplied together give the expression we are looking for, which is the sum of every possible bet. The basic factors of our bet are 6, 7.5,9 and 8 to each of which you need to add 1 and then multiply them all together then subtract 1.
Thus 7 x 8.5 x 9 x 8 = 5335, and 5335 -1 = 5334. So if your betting unit was £1 you would have won £5,334, a very healthy return on investment. Furthermore bookmakers often add bonuses to Lucky 15 bets so your return would be even higher.
Fortunately it is not necessary to calculate these bets out as there are many free full cover bet calculators available on the web.