by Jessica Martini, Christina Bossinakis & Jill Williams LEXINGTON, KY - Following another day of competitive bidding, the two-session Book 1 section of the Keeneland September Yearling Sale concluded Tuesday with double-digit increases over its 2023 counterpart. A colt by Curlin brought the section's top price when selling for $5 million to Mandy Pope's Whisper Hill Farm. The sale topper was one of four by the Hill 'n' Dale stallion to bring $1 million or more on the day and, with a further 16 yearlings bringing seven figures Tuesday, Book...