Round robin: what you are actually placing

A round robin takes a list of selections and generates every combination of a chosen size, then places each combination as its own separate parlay. Three selections 'by twos' produces three doubles; four selections by twos produces six. The stake you enter is per combination, and the total outlay is that stake multiplied by the number of combinations.

It exists to convert an all-or-nothing parlay into a structure with partial credit. If one selection loses, only the combinations containing it are dead, and the rest can still return. What you buy is survivability; what you pay is the vig on every one of the slips instead of on one.

The break-even point sits higher than intuition suggests. With four selections by twos you need three of four just to show a modest return, and going two-for-four — a fifty per cent hit rate — is a loss of nearly forty per cent of the outlay.

That is also the expensive part. The stake box says 10 and the slip costs 60. Five selections by twos is ten combinations; five selections in doubles, trebles and four-folds together is twenty-five slips. People routinely place several times the money they intended because the multiplier is displayed after the stake rather than before it.

What to do with it. Count the combinations, multiply by the per-line stake, and read that total before confirming.