Mark Immelman is the Host of The On the Mark Podcast, and a Golf Magazine 2021 "Teacher to Watch". He shares anecdotes and lessons from his experiences on the PGA TOUR in 2021. Mark highlights some of the most memorable shots he called while on-course. He also shares tips from Golf.com columns he wrote in the first quarter of the year. Mark shares his insights on: Upright Swing Planes (Justin Thomas), Fairway Metal Play and the Use of Lofted Metal Woods (Si Woo Kim), Surviving and Beating Slumps (Brooks Koepka), Making Swing Changes Successfully (Jordan Spieth), and Practicing One-Arm shots for Improved Pitching and Golf Swings (Cam Smith).