U.S. Army Staff Sgt. Matthew Cassidy of the 2-310th, 86th Training Division guards an open doorway during a simulated extraction mission on February 6th, 2017 on Ft. Hunter Liggett, Calif. Cassidy competed in the 91st Training Division's Best Warrior Competition that assessed his proficiency in warrior tasks and drills. (U.S. Army photo by Spc. Derek Cummings/Released)