Apprentice

A new jockey who has not ridden a certain number of winners in a specified time period.

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.

Bobble/Stumble

A slip or a duck from a horse trying to leave the starting gates, often caused by the surface giving way under the feet. This can range from a mild misstep to a stumble down to their knees.