ubetido

The trifecta formula suggested above is theoretically correct but in practice is seriously flawed.

If the odds of a horse are long odds on then the chances of that horse finishing third are substantially over estimated by the formula. Odds on chances don't run third very often, they win more than 50% races, run second a lot and so on. It is sometimes the case where, depending on the odds structure of the race, a 20/1 chance has the same chance of running third as the long odds on runner. But the given trifecta formula does not reflect such a reality.

Moral of the storey - dont put short priced favourites in for 2nd or 3rd in trifecta combinations as they represent poor value.

Disclaimer - I'm no expert.