As far as marketing for a nascent, unorthodox racehorse ownership venture goes, you couldn't do much better than a horse carrying your silks into the Churchill Downs infield as the GI Kentucky Derby winner. That's what Michael Behrens experienced Saturday, as Authentic (Into Mischief), bought into by his MyRacehorse microshare partnership in June, fought off favored Tiz the Law (Constitution) past the Twin Spires to earn the garland of roses. Wednesday, Behrens joined the TDN Writers' Room podcast presented by Keeneland as the Green Group Guest of the Week to...