Iron play is perhaps the most underappreciated part of the game. We all admire long, towering drives. We know that wedges, the "scoring clubs," can erase mistakes. And as we've heard repeatedly, you "putt for dough." In fact, iron play -- or approach shots -- accounts for the biggest scoring difference between the best pros and average pros. It's been a secret for so long in part because iron play has been the hardest aspect of the game to measure.
Not anymore. I've been consulting with the PGA Tour for quite some time on their implementation of Strokes Gained statistics. The Tour recently changed the golf-stats game by making their biggest upgrade in performance information in years. Since 2011, Strokes Gained putting data has been available to the public. But since June (at pgatour.com), the Tour has made Strokes Gained stats in three critical categories accessible: driving (which the Tour calls "off the tee"), approach shots ("approach the green") and short game ("around the green").
Why is this newfangled data so revelatory, and how does it work? Let's imagine two Tour pros playing a 170-yard par 3. Pro A hits the green 33 feet from the hole and sinks the putt for birdie. Next, Pro B hits the green one foot from the hole and taps in for birdie. Both pros get credit for one green in regulation and one putt. But those traditional stats -- GIR and putts per round -- completely obscure the two very different ways the birdies were made.
Strokes Gained measures progress to the hole in strokes, not distance, because strokes are the only units that really matter in scoring. Both of our pros started three strokes away from the hole, the average score of pros on the 170-yard hole. Pro A's tee shot finished two strokes away from the hole, because the average number of strokes needed to hole out from 33 feet on the green is two. When he sunk the 33-footer, he gained one stroke, because he took just one putt, compared with the average of two.
Pro B's tee shot went from three strokes away from the hole to one stroke away from the hole, because the average strokes needed to hole out a tap-in is one. This means that Pro B's tee shot was one better than expected, i.e., it gained one stroke. Pro B took one putt from tap-in range, compared with the average of one, so he gained zero strokes with the putt. In the end, both pros gained one stroke on the hole with their birdies. But Strokes Gained shows that Pro A did it with an average iron shot and a great putt, while Pro B did it with a great iron shot and an average putt.
The Tour now lets you take a deep dive into Strokes Gained data for every player. There are many seemingly small nuances of play that have huge impacts on scoring. Consider: The best pros gain the most strokes over their competitors with their approach shots, and the Strokes Gained leaders in this category earn more prize money than leaders in other categories.
Now that Strokes Gained lets us accurately measure a wide range of categories, the importance of iron play won't be a secret. In fact, loads of new secrets await. So have at it, stats lovers.
The truth is out there.