'TDN Rising Star' Sierra Leone (Gun Runner) checked off quite a few boxes on his GI Kentucky Derby development checklist with Saturday's half-length score in the GII Risen Star S. at Fair Grounds. In just his third career start, he handled shipping away from his home base, winning as the 5-2 favorite off an 11-week layoff, rating from mid-pack while equipped with blinkers for the first time, and racing under the lights on a sloppy, sealed and eerily shadowy track. And yet, jockey Tyler Gaffalione still believes there's room for...