LOUISVILLE, Kentucky--What started as a chance encounter one year at the GI Kentucky Derby has blossomed into a very successful partnership between Brad Stephens of Six Column Stables, Randy Bloch and a rotating group of other enthusiastic owners. They'll return to Churchill Downs on Saturday with Champagne Problems (Ghostzapper), who goes in the GI Breeders' Cup Distaff before being offered Sunday at Fasig-Tipton November through Hill 'n' Dale Sales Agency as hip 172. "One of my first trips to the Kentucky Derby was the year Street Sense won," recalled Stephens, a...