Mastering the mental game

There is one man who will be pacing around the Hazeltine National Golf Club in Minnesota this week hoping to make it three majors in a row — but you won’t find his name when you trail your finger down the list of starters at the 91st PGA Championship. Though his presence may be unnoticed by spectators lining the fairways, his influence on the players he coaches is becoming far more conspicuous.