Schy was supportive of the experiment, so a set of old clubs was chopped up in the name of science. Into some old Nike VR heads they inserted 37.5-inch shafts, which is the length of a traditional 6-iron. In any set, the heads of the wedges are heavier than those of the slender long irons. After running a series of calculations in the supercomputer that doubles as his brain, DeChambeau determined that an ideal uniform weight for the heads in a single-length set would be 282 grams. Lead tape was used to make the heads on the longer irons heavier; the extra mass made up for a shorter swing arc. To shed weight on the wedges, holes were drilled in the back of the head and metal was gouged out of the backline of the sole; losing that mass was counteracted by the increased swing speed that came with the longer shaft.

When the work was complete, DeChambeau raced to the first fairway at Dragonfly Golf Course, the humble public track he grew up haunting in Madera, Calif. From 160 yards, he selected an 8-iron. The club felt a little long and light but not overly so. He hit a lovely draw pin-high. On the second hole he dropped a ball 210 yards from the flag and reached for his reconstituted 5-iron. This was the moment of truth: If the shorter, heavier long irons worked, his underlying theory of a single-length set was sound.

DeChambeau flushed the shot. “It was in the air for what felt like forever,” he says. The suspense was awful. Was the ball going to be 20 yards short? Twenty yards long? It landed three feet from the flag.

Less than a decade later, single-length irons are a rapidly growing part of the equipment market. DeChambeau didn’t invent the concept—Tommy Armour Golf tried (and failed spectacularly) to sell a version in the 1980s—but he is now the public face of a fundamentally different way of playing the game. He has had some help along the way. While an undergrad at SMU, DeChambeau became close to David Edel, a fellow obsessive whose Texas-based boutique company has long turned out some of the most gorgeous (and expensive) putters and irons on the market. Edel spent years perfecting the single-length clubs that DeChambeau used to win the 2015 U.S. Amateur and NCAA title, going through three dozen handcrafted sets. From the beginning, Edel could feel a revolution brewing that transcended DeChambeau’s idiosyncrasies.

“One of the hardest things for amateurs is to consistently produce a good strike with their irons,” says Edel. “On every swing the club feels different, because it is. With a wedge you have to squat down and stand close to the ball, and it’s a short, heavy club. With a long iron you’re more upright, the ball is farther away, and the club is long and light. No wonder people struggle! Eliminating all of those variables automatically makes the game easier. That is the holy grail of golf equipment, and we found it.”