It started with Jhonattan Vegas and William McGirt. Then Brendan Steele surged ahead. Then Hunter Haas was briefly on top as he chased a 59. Now Kevin Na, in the clubhouse after an 8-under 63, and Vegas, who tapped in for a birdie on No. 9 to complete a 67, are tied for the lead at 12 under. Joining them in the dozen-under club, but still on the course, is Charlie Wi. The South Korean is 5 under for the day and is about to tee off on the 444-yard par-4 18th. If Wi can’t move ahead, maybe McGirt can. He’s at 10 under with four holes remaining in his second round. If neither Wi nor McGirt moves ahead, 12 under looks like it will be the number for at least a couple more hours.