Formula for predicting the winnings of a trifecta?

Question

hi,

does anyone know of an approximate formula for predicting how much a trifecta (correctly predicting the first 3 horses in a race) may pay in horse racing?

ie, calculated from the win/place odds of the horses involved, the number of horses in the race, etc.

i'm primarily after it for harness racing, but I'm sure the calculations are the same for gallops or harness racing.

i'm sure i've heard of a fairly straightforward formula in the past, anyone know it?

Answer 1

The track has it`s own trifecta pool. Let`s use an 8 horse field as an example for some probable trifecta payoffs.  

Horse 1. 5-1 odds

Horse 2. 40-1

Horse 3. 7-5(the favorite).

Horse 4. 10-1

Horse 5. 3-1

Horse 6. 2-1

Horse 7. 15-1

Horse 8. 9-1

If you won the 3-6-5 trifecta in this race you could expect a low payoff(somewhere in the $40 range on a $2 bet. as many bettors would have predicted this order of finish. However, if you won on a 2-7-8 combination, you could expect to pick up about $2000.