Baltimore is the center of the thoroughbred racing world today as Pimlico Race Course presents the Preakness Stakes and six other stakes, with numerous local runners involved on the 13-race program that begins at 10:30 a.m.

While Kentucky Derby runner-up Hard Spun seeks revenge against Street Sense in the Preakness, Chelokee appears best in the Barbaro Stakes, the ninth race on the card (post time 3:37 p.m.).

Chelokee is trained by Michael Matz, who conditioned last year's Kentucky Derby winner, Barbaro, who broke down in last year's Preakness before being euthanized in late January following months of attempted recovery.

Barbaro's owners, Roy and Gretchen Jackson, will present a trophy to the winner of the Barbaro Stakes, so Matz could be the recipient.

Here's a look at some of the races on the undercard:

In the eighth race, Diabolical, the winner of Philadelphia Park's richest sprint, the Gallant Bob Handicap last year, faces seven speedsters in the Maryland Breeders' Cup Sprint Handicap.

Mario Pino, the rider of Hard Spun, will be aboard Diabolical for trainer Steve Klesaris.

Max West, considered by some the best claim in the history of Philly Park, deserves an upset chance in the Baltimore City Turf Sprint, the fifth race on the program.

Claimed for a mere $6,250, the gray gelding has earned over $200,000 but broke slowly after a layoff in a stake at Atlantic City Race Course on May 3.

Xtra Heat won added-money races at Delaware Park and throughout the Mid-Atlantic region, and her son, Southwestern Heat, starts from the rail in the Hirsch Jacobs Stakes at six furlongs, the sixth race on the card.

Xtra Heat captured 25 stakes during her career, a record for a female runner, and missed by just a half length in the 2001 Breeders' Cup Sprint.

Hobbitontherocks, also in the Jacobs, was claimed for $25,000 by Ramon Preciado last October at Philly and just missed in his last two starts in stakes at Pimlico and Aqueduct.

Borel wins debut at Pimlico. Calvin Borel, who guided Street Sense to victory in the Kentucky Derby, captured his first mount ever at Pimlico yesterday when he led throughout aboard Unbridled Sidney in The Very One Stakes on the turf.

He failed in the next race on the main track, the Miss Preakness Stakes, aboard Magnetic Miss.

Time's Mistress, with Mark Guidry, took the Miss Preakness with Silver Knockers second and the odds-on favorite Your Flame in Me out of the money.

Breast Cancer Research Day. Last Sunday's charity event at Philadelphia Park raised about $6,100 from multiple sales, silent auctions, and activities throughout the afternoon.

Lynda Martin and Nikki Yager worked tirelessly through countless hours in support of the event which included a jockeys' foot race won impressively by Eriluis Vaz.

Contact staff writer Craig Donnelly at 215-854-2839 or cdonnelly@phillynews.com.