A Four-Fold Accumulator is one bet made up of four selections in different events. If they all win, so do you. But if any of the selections lose, your bet does too.
A Rule 4 deduction is applied when a horse is withdrawn from a race after the time of your bet. The deduction is a percentage of your stake, and can be calculated by applying the odds of the withdrawn horse at the time of withdrawal from the chart below.