"Foley...is among the most technical and scientifically oriented coaches in golf."

Thanks to reader John for John Paul Newport's Saturday column on Sean Foley.

Specifically, his overlooked work helping Justin Rose become one of the game's top players.

When I asked him to explain Rose's rise over three years from 67th to 19th to fifth in one measure of long-iron excellence. Foley gave me a one-word answer: "Myelin."

Excuse me? "That's the insulation that wraps around neural brain circuits and helps them fire faster when presented with certain stimuli," he said. Laying down more myelin, over time, helps secure new skills; that's the value of those reps Woods always talks about. " 'Swing change' is really a stupid term, because it's actually just gradual evolution in encoded brain patterns," Foley said.