Judging a service by its strike rate

A strike rate with no price attached is a number with no unit. Fifty-two per cent at −110 makes money. Seventy per cent on −400 favourites loses it, steadily, for as long as it continues.

The break-even rate moves with the price. At −110 you need 52.4 per cent; at −400 you need 80. So a record is only interpretable once you know what was being backed, and the price is the half that is almost never printed.

It is not that strike rate is meaningless. Inside a single price band it is genuinely informative, which is why a service that publishes its average price alongside it is saying something real.

That is also the expensive part. It is the most advertised statistic in the industry and the least interpretable, and those two facts are related. A number that cannot be checked is a number that can be chosen.

What to do with it. Ask for the average price before the percentage. If it is not offered, the percentage is decoration.