Orb, this year's Kentucky Derby winner, is the heavy odds favorite.
While the field is less crowded, several horses are capable
of pulling off an upset.
Joel Rosario rides Orb during the 139th Kentucky Derby at Churchill Downs Saturday, May 4, 2013, in Louisville, Ky. (AP Photo/J. David Ake)
138th Preakness Stakes - Previews
BALTIMORE, MD - MAY 16: Jockey Kevin Krigger takes Preakness entrant Goldencents over the track in preparation for the 138th Preakness Stakes at Pimlico Race Course on May 16, 2013 in Baltimore, Maryland. (Photo by Rob Carr/Getty Images)
Jockey Rudy Quevedo rides Kentucky Derby entrant Oxbow for a workout at Churchill Downs Thursday, May 2, 2013, in Louisville, Ky. Saturday will be the 139th running of the Kentucky Derby. (AP Photo/Morry Gash)