Complex sentence: The Suburban Handicap is a Grade I stakes race for Thoroughbred race horses aged three and older run at the classic one-and-one-quarter mile distance on the Belmont Park dirt for a $400,000 purse.
Split into simpler sentences: The Suburban Handicap is a Grade I stakes race for Thoroughbred race horses aged three and older. It is run at the classic one-and-one-quarter mile distance on the Belmont Park dirt for a $400,000 purse.