OWINGS MILLS, Md.—No one ever questioned that Patrick Cantlay had the chops to be among golf’s elite. What he might have lacked in a number of PGA Tour victories, he made for it with the way he won or the field he beat. His victory Sunday in the BMW Championship—the fifth of his career and his PGA Tour-leading third of the season—was a little of each. On a Caves Valley course that suited the biggest hitters, facing the biggest masher of them all in Bryson DeChambeau, he delivered a moment that will be remembered for the ice in his veins and nerves of steel. He really only smiled after he made the last of six pivotal putts on the final nine holes—six of them in a sudden-death playoff. “I’m just as focused as I can be. If I look the way I do, it’s because I am locked in and …