After graduating from the University of Wisconsin LaCrosse (LaCrosse State University) in 1973, Osborn Shackelford began his teaching and coaching career at Maryvale High in Phoenix Arizona. In 1979, Coach "Shack" became the third head coach for the Maryvale women's basketball program. He coached the Lady Panthers from 1979-2003 and had a 64.3 winning percentage. During his tenure, Maryvale won two invitational tournaments, 2 region titles, and were the state champions in 1989 and 1990. The Lady Panthers lost in double OT in the state semifinals in 1993. Coach Shack has coached in the ACA All-Star games as a head coach and as an assistant. He was the Arizona Coaches’ Association coach of the year in 1993. Oz was the chair of the ACA women's basketball committee before retiring in 2003. Coach Shackelford is currently serving on the Executive Board of the Arizona High School Coaches Hall Of Fame. He inherited the job of the annual Hall of Fame Golf Tournament organizer.

Shack’s parents, Osborn and Charlie Lue, siblings, Karen and Aaron, his wife Denise and son AJ have strongly supported him throughout his teaching and coaching career.

These are the coaching activities by Coach Shackelford:

Volunteer freshmen football 1973-76 Freshmen/jv baseball 1973-78 Freshmen/jv boys’ basketball 1976-1990 Freshmen women’s volleyball 1983-2003

Varsity women’s basketball 1979-2003 Jv/freshmen wrestling 2003-present. Jv/freshmen football 2006, 2011-present

Coach Shack was nominated by his peers and inducted into the National High School Coaches Hall of Fame in Lincoln, Nebraska in 2020.