McGill is best known for his invention of the McTwist (a 540 air), which he learned while teaching skateboarding at a Swedish summer camp in 1984. When he returned to the US, he officially unveiled The Trick at the Del Mar skatepark contest in August of that year. The McTwist was a ground-breaking maneuver which took skateboarding to new heights and became essential to winning vert contests in the mid 80s.