Kentucky Downs plans to increase purses for nine of its 18 stakes by a total of $3.7 million from what was originally announced, pending regulatory approval, according to a press release from the track early on Thursday morning. Leading the way is the GIII Nashville Derby Invitational, bumped from $2.5 million to $3.1 million. That would make the 1 5/16-mile stakes North America's second-richest race, for Kentucky-breds, behind only the $5 million GI Kentucky Derby among races held at one track. The Nashville Derby already was America's richest turf race...