Today's SE - Amal Horse Racing Picks

Apprentice

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

Exercise Rider

A rider built much like a jockey but is employed for exercising and working out horses in the morning.

Pari-Mutuel

A pool style wagering system, where all money input through betting is divided among those with winning tickets (save for various deductions by the track operators).