At the Ryder Cup every little detail becomes an obsession, from the pleats in the golfers’ pants to how the pin positions favor the collective ball flights of the home team. No minutia is insignificant … unless you’re Dustin Johnson and his brother-caddie, Austin, golf’s most laconic characters. During last year’s event at Hazeltine, Dustin faced a sloping mid-length putt that plainly had two or three feet of right-to-left break. After conferring with his brother, he started his ball a yard left of the hole, missing the putt by at least six feet. Had the tension short-circuited his stroke or perhaps clouded his vision, even though this was just a practice round? In his soft South Carolina drawl, Dustin offered his caddie a different explanation: “Awwwww, man, I had the [green-reading] book upside down.”