Curlin is an American Thoroughbred racehorse who was the American Horse of the Year in both 2007 and 2008. He retired in 2008 as the highest North American money earner with over US$10.5 million accumulated. His major racing wins included the 2007 Preakness Stakes, 2007 Breeders' Cup Classic, and 2008 Dubai World Cup. In August 2008, Timeform assigned a 134 rating for Curlin, calling him the best horse in the world on dirt. Curlin was elected to the National Museum of Racing's Hall of Fame in 2014, his first year of eligibility.

Exaggerator is a retired American Thoroughbred racehorse, winner of the 2016 Preakness Stakes. Racing as a two-year-old in 2015, he won three of his six starts including the Saratoga Special Stakes and the Delta Jackpot Stakes as well as finishing second in the Breeders' Futurity and fourth in the Breeders' Cup Juvenile. The following spring, he finished second in the San Vicente Stakes and third in the San Felipe Stakes before establishing himself as a contender for the 2016 Kentucky Derby with a six length win in the Santa Anita Derby. After finishing second to Nyquist in the Derby, he turned the tables to win the 2016 Preakness Stakes. He ran poorly in the 2016 Belmont Stakes but defeated Nyquist again in the Haskell Invitational. Tactically, Exaggerator was a "closer" – one who prefers to come from behind in his races.