Bug

An apprentice jockey.

Minus Pool

A pari-mutuel pool – typically a show pool - where one horse is so heavily bet that after deductions there is not enough money left to cover the prescribed minimum on each bet.

Superfecta

A wager involving choosing the first, second, third, and fourth horses in one race in the exact order. A superfecta box involves paying more to ensure they can finish in any order in the top four spots.