Santa Anita Park will deny computer-assisted wagering accounts access to win pools with two minutes to post at the track's fall meet, which begins Sept. 26.
The change was first reported by Daily Racing Form.
CAWs use data to analyze races and place high-volume, large-value bets—often thousands within seconds—just before betting closes on a race using sophisticated wagering technologies.
CAWs have been a point of contention for bettors, who have seen dramatic odds changes in the final moments before a race.
BloodHorse reported that Nanci Griffith, winner of the sixth race July 26 at Del Mar, sustained "perhaps the most glaring odds drop" when her odds went from 18-1 to 6-1.
DRF noted the plan is a "continuation of a policy enacted by Del Mar in late July after several instances in which win prices changed dramatically between the time the field was being loaded into the gate and final odds were determined."
Del Mar enacted its policy July 29. The New York Racing Association also has a similar policy in place. Santa Anita did not previously have a policy regulating CAW access.
"This is part of an overall effort to ensure an optimal wagering experience for fans on-track, at simulcast locations, and those playing via our advanced-deposit wagering partners," Del Mar president Josh Rubinstein said at the time.
CAW accounts "provide up to" 30% of handle on Thoroughbred racing, according to DRF.
