chalk
Wagering favorite in a race. Dates from the days when on-track bookmakers would write current odds on a chalkboard.
chalk player
Bettor who wagers on favorites.
chart
A statistical “picture” of a race (from which past performances are compiled), that shows the position and margin of each horse at designated points of call (depending on the distance of the race), as well as the horses’ age, weight carried, owner, trainer, jockey, and the race’s purse, conditions, payoff prices, odds, time and other data.
commingle
Combining mutuel pools from off-track sites with the host track.
Comparable Index (CI)
Indicates the average earnings of progeny produced from mares bred to one sire when these same mares are bred to other sires. A CI of 1.00 is considered average, 2.00 is twice the average, 0.50 half the average, etc.
consolation double
A payoff to holders of daily double tickets combining the winning horse in the first race of the double with a scratched horse in the second.
coupled (entry)
Two or more horses running as an entry in a single betting unit.