Editor’s note: This story originally appeared in the “Live From with Rex and Lav” newsletter from the PGA Championship. Sign up for more insight and entertainment during golf’s biggest events. NEWTOWN SQUARE, Pa. – His hands clasped behind his back, unfailingly polite, Aaron Rai is ticking through his final-day exploits on the 18th green at Aronimink. The perfectly shaped drives. The pinpoint approaches. The birdie bombs. With millions watching around the world, he is calm, confident, clearheaded.