Accumulator bonuses, and what they hide

An accumulator bonus adds a percentage to the return on a multiple, rising with the number of selections. The ladders published here run from a couple of per cent at two legs to figures past a thousand per cent at the long end.

The number that gets advertised is the top of the ladder, and the top of the ladder is reached at a leg count almost nobody plays. What matters is the rung a punter actually stands on, which for most slips is two to five legs and pays single digits.

The more important point is compounding in the wrong direction. Margin applies to every leg. A five-leg multiple at a book charging five per cent a leg carries far more than five per cent of built-in cost, because each leg’s price has already been shaded before they are multiplied together. A bonus applied at the end is being applied to a return that the margin has already reduced several times over.

That is not an argument against accumulator bonuses. It is an argument for reading them at the leg count you actually play, at the book whose price you actually get, rather than at the top rung of a ladder in an advertisement.