The club’s sole is the bottom of the club head, explains PGA.com’s golf glossary. When a golfer addresses the ball, the sole is the portion of the club that lays on the ground. Its width is measured from the leading edge -- where the sole meets the club face -- to the sole's trailing edge toward the back of the club. Club manufacturer Ping led the trend to wider-sole clubs in the first decade of the 21st century, according to the Golf Channel’s Adam Barr, and was quickly followed by Callaway, Wilson and others.
Higher Iron Shots
A wider -- and presumably heavier -- sole lowers a club’s center of gravity. As a result, it is be easier to hit your iron shots into the air, according to separate articles by "Golf Digest" writers Mike Stachura and Max Adler. Adler warns, however, that if the center of gravity falls too low, “you start to lose ball speed.”
Wide-sole clubs are generally classified as game improvement or super game improvement equipment, as opposed to the thinner soles that professional and low-handicap players generally prefer, as Stachura notes. “If you're really looking for game improvement, focus on sole width,” Stachura adds.
Noted swing coach Butch Harmon recommends that players replace long irons with hybrid clubs, in part because of their wider soles. He says that “if you do mishit it, the hybrid's wide sole and low center of gravity will minimize the damage.”
A wide sole helps the club bounce off the ground on contact, rather than cut into the turf and hit a fat shot, says Stachura. Club designer Tom Stites notes that while the wider sole “doesn’t change the degrees of designed-in bounce angle,” it does “keep the sole from digging” into the turf. This aspect of wide-sole clubs helps players who sweep their fairway shots rather than hitting down on the ball, says Barr. The wide sole's superior bounce also makes it a better choice for golfers playing on softer ground, as a narrower sole is more likely to slice into the turf, like a knife.