Staff Sgt. Daniel Czech, Northern Strike opposing force (OPFOR) member, ambushes a convoy from the 120th Field Artillery Regiment, Wisconsin National Guard, during NS 23-1, Jan. 26, 2023, at Camp Grayling, Mich. OPFOR is designed to build readiness for visiting units by introducing injects meant to challenge soldiers in a variety of ways. (U.S. National Guard photo by Staff Sgt. Tristan D. Viglianco)