Kentucky Derby and Breeders' Cup Classic winner Authentic (Into MIschief--Flawless, by Mr. Greeley) has been retired to Spendthrift Farm, where he will stand for a fee of $75,000 S&N, the farm announced Monday morning, two days after his Classic win. He arrived at Spendthrift at around 10 a.m. Monday, led off the van by his trainer Bob Baffert, who proclaimed, "There he is. The best horse in America." "Authentic is a once-in-a-lifetime kind of horse, and Mr. Hughes is very proud that we are able to share him with 5,300-plus...