Pool Play was impressive in his dirt debut (Reed Palmer Photography/Churchill Downs)

Mark Casse's decision to run William Farish Jr.'s POOL PLAY (Silver Deputy) in Saturday's 30th running of the Stephen Foster H. (G1) at Churchill Downs was not a wild stab or a whim, as racing fans across the country discovered when the six-year-old stormed through the stretch to edge Mission Impazible (Unbridled's Song) by a neck at 36-1 odds.

A three-time winner of the Sovereign Award that annually honors Canada's top trainer, Casse sent Pool Play to the Foster with a specific mission -- to determine how the distance-loving horse, after 27 races on synthetic and turf courses, would fare on a dirt course. If he ran as well over the Churchill Downs dirt as Casse hoped, a bid for the $5 million Breeders' Cup Classic (G1) at the Louisville, Kentucky, track on November 5 could be in the works.

Pool Play handled Saturday's initial test with aplomb when he posted the third-largest upset in the three-decade history of the Stephen Foster. On Sunday, Casse was working up a plan to get him to the next step.

"It's nice when things work, when you have a plan and it works," Casse said on the morning after his most important win at Churchill Downs. "I understood him being that big a price. Here's a horse running against some of the best older horses and they all had proven form on the dirt. Well, here we had a horse who had never ran on it, so I could understand."

Along with watching Pool Play blossom from an unknown factor to Breeders' Cup Classic contender in the Foster, the upset was special to Casse for personal reasons. The Indianapolis native spent his early years as a trainer beneath the historic Twin Spires, and has a 1988 spring meet training title so show for it.

Pool Play could be BC Classic bound (Reed Palmer Photography/Churchill Downs)

"I was out there (on the Churchill dirt) this morning watching horses train and you can see they get into the ground only about two inches, at most," Casse said. "If you walk across Churchill Downs and you walk across Woodbine's racetrack, that's how much they penetrate the surface. It's almost identical."

It's Casse's opinion the clay is an important part of the make-up of Churchill Downs' sandy loam surface and is the key ingredient that makes the Louisville surface comfortable to horses that do their best running on synthetic or turf courses, or possess pedigrees that point toward those surfaces.

Whatever the case, Casse's plan worked well for Pool Play in the Stephen Foster. Now he's looking to formulate a plant over the coming weeks that will get his veteran back to Churchill Downs and ready to offer his best effort against an expected international field the Breeders' Cup Classic.

"We've been planning to go to Saratoga with a string, so what I think I'll do is take him to Saratoga and see how he trains over the dirt," Casse said. "Just because you like the dirt at Churchill Downs doesn't mean you're going to like it at Saratoga. We'll train him there and if he trains all right we'll think about the (August 6) Whitney (G1).

"Our number one goal will be the Breeders' Cup. How we get there is kind of secondary, really. So everything we do from now on will be that kind of plan. I wouldn't even be shocked if he ran on the grass again."

The winner's share of the Stephen Foster purse boosted Pool Play's career earnings to $909,556 to go along with his 6-6-5 record from 28 starts. His only other graded win came in the 2009 Durham Cup (Can-G3) at Woodbine. In his previous start, Pool Play finished second in the grassy Elkhorn S. (G2) at Keeneland.