From The New York Times:

How would Zenyatta perform against great racehorses like Citation and Cigar? To answer that, Horse Racing Simulation and the National Thoroughbred Racing Association have created a virtual simulation of Zenyatta racing against nine top thoroughbreds throughout history.

The simulation used more than 100 data elements in a proprietary computer program, said Mike Calderone, president of Horse Racing Simulation.

“The simulation replicates the true attributes of each contender and generates a probable pace scenario and jockey strategies that lead to the most logical and accurate race result,” he wrote in an e-mail message.

The race is set at Pimlico over a mile and three-sixteenths. The track is fast. The field includes Zenyatta, Seabiscuit, Cigar, Rachel Alexandra, Big Brown, Barbaro, Ruffian, Smarty Jones, Citation and Affirmed. The horses are at the post.