Apprentice

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

Bullet

A bullet, or bullet workout, is a workout that was clocked as the best time for a certain distance on a given day.

Main Track Only

A horse entered for main track only (MTO) is one hoping the weather forecast or track conditions will move the race off the turf course and onto the main track. They are scratched the morning of the race if the conditions stay dry.