Bolt

A sudden veering to the inside or outside rail, often caused by the horse spooking or shying from something.

Also Eligible

A horse that is entered but does not draw into the body of the field due to too many entries, and thus is not permitted to start unless there are enough scratches to shrink the field size.

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.