Horse racing is awash with hoary, oft-repeated strategies that supposedly represent a licence to print money, despite evidence to the contrary. Possibly the ‘oldest chestnut’ of all is the maxim ‘Always back the outsider of three’, which only retains merit by virtue of being passed down from one generation of punters to the next.
Perhaps the first thing to say about three horse races is that, in the event of insufficient declarations, some, but not all, races may be reopened for a short period at declaration time, so three-horse races occur less frequently than was once the case. The premise for always backing the outsider is that, due to lack of numbers, three-horse races are rarely, if ever, run at an end-to-end gallop. Conventional wisdom dictates that a muddling, tactical affair, which turns into a sprint to the line over the final few furlongs, is less likely to produce reliable, repeatable form than only that is truly run throughout. Obviously, all three runners are affected, but the outsider may be disadvantaged least of all, or even advantaged, by the way in which the race is run.
However, the truth of the matter is that the outsider wins approximately three in twenty, or 15%, of three-horse races and, more often than not, represents poor value-for-money. Of course, it is possible that blindly following such as strategy can produce a profit, at least for a while, but strict statistical analysis of the results reveals that any such profits are due, in large part, to pure luck. In other words, while it may be possible to develop a profitable strategy – by, say, concentrating on handicap races and/or avoiding outsiders priced at 16/1 or longer – the ‘outsider of three’ theory, alone, will eventually empty your betting bank.