What golf ball did Jack Nicklaus use?

A MacGregor ball, for every one of his 18 major championships.

Nicklaus was a MacGregor staff player for most of his career. The company’s Tourney and later Nicklaus-branded balls were wound balata, a center wrapped in rubber thread under a soft balata cover, which was the standard tour construction until solid-core urethane balls arrived in 2000. The ball his son handed to a young fan during the final round of the 1986 Masters was a Nicklaus Tour Balata 392.

The strange part of the story is that the ball was not very good. Golfweek’s history of MacGregor reports that Ben Hogan refused to play it, that other staff players switched balls after the first hole, and that a USGA machine test of balls collected at the 1977 U.S. Open found some curving as much as 15 yards off line. Frank Thomas, the USGA’s technical director, said he believed Nicklaus “would’ve won several more majors if he had played a better ball.”