Dustin Johnson a big presence on a big golf course (The Associated Press)

View photosMoreDustin Johnson watches his drive off the tee on the fifth hole during the second round of the BMW Championship golf tournament at Crooked Stick Golf Club in Carmel, Ind., Friday, Sept. 9, 2016. (AP Photo/AJ Mast)CARMEL, Ind. (AP) -- Roberto Castro kept pouring in birdies and expanding his lead in the BMW Championship until he finished with another 7-under 65 and led by as many as five shots as the other players at Crooked Stick were finishing their rounds.

By the end of the day, U.S. Open champion Dustin Johnson had set the course record at 63 and was tied for the lead.

Johnson was asked to put himself in Castro's place. If he had never won in 125 starts on the PGA Tour, had a…