Only pregnant ladies are ‘due’

Only pregnant ladies are due

“We’re definitely due here mate.”

That saying, or words to the same effect, is used on racetracks and TAB’s every day of the year. It normally comes from a punter who has backed a handful of losers in a row, which leads him to mistakenly believe that somehow this means that his next bet is more likely to win. Unfortunately there is no sound logical or mathematical reason behind such a statement, rather it’s more likely the hopes of a desperate punter.

In the short-term, being ‘due’ means nothing. However over a larger sample size there is likely to be a ‘reversion to the mean’. I’ll use a coin toss once again as a demonstration. If you tossed 10 heads in a row, the chance of the next toss being another head is 50%. Nothing more nothing less, despite the fact tails backers would believe they are due. However if you had 10,000 tosses and say 55% came up heads, you would reasonably expect that over the next 10,000 tosses there would be a reversion to the mean, because long term you will get 50% heads and 50% tails. Relate that back to horse racing and although you might have backed 10 straight losers and believe that you’re ‘due’ since you normally have a strike-rate of about 30%, this concept doesn’t apply in the short term.

However if you’d won only 10% of your bets for the last 3 months, you could reasonably expect that your next 3 months would see a far better strike-rate (possibly exceeding 30%) as you trend back towards your long-term average. Hope is not a strategy. And relying on the belief that you’re ‘due’ is not sensible for punters, only pregnant ladies.