The 7-iron speed rule you're probably not following
Golf Digest senior writer Alex Myers is on a one-year mission to see how good he can get at golf through daily training, practice and playing. Read more from his “Late Scratch?” series here.
I’ve spent much of this offseason trying to gain speed, possibly even too much time. But despite all my work both in the gym and in the sim to hit the golf ball longer, I was recently made aware of an obvious hole in my practice.
The whole goal of speed training is to move the club faster to make the ball go farther. But which club?
As I learned during a session with Quaker Ridge Golf Club head pro and one of Golf Digest's Best Teachers in New York, Mario Guerra, I needed to expand my thinking. And I learned a valuable—and easy—math lesson that can help all golfers.
How fast do you swing your irons?
You probably don’t know. Heck, I had no clue. While most golfers are conditioned to concentrate on driver clubhead speed for their driver, they often neglect to even think about the other clubs in their bag.
I realized this recently while hitting some iron shots into a simulator screen. While the distance numbers seemed great to me and the high smash factor told Mario I was getting about as much as I could out of each strike, he was surprised by my lack of swing speed.
I was swinging my 7-iron about 75 mph, which didn’t mean anything to me. I also just assumed that I swung my irons at the same speed proportionately to my driver. But I assumed wrong.
“You’ve gotten used to swinging easy because the ball is still going pretty good,” Guerra said to me. “But imagine how far you’ll hit it if you swing as fast as you should?”
Which leads to the next question . . .
How fast should you swing your irons?
J.D. Cuban
Remember it was Mario who taught me the physics lesson about club path and face angle that helped me understand ball-striking better? Well, don’t worry, because this math lesson he gave me to figure out how fast you should swing your irons is a lot easier.
Guerra told me the general rule is that you want your 7-iron swing speed to be 20 mph slower than your driver swing speed. So, using me as an example, if my goal is to swing my driver at 105 mph during rounds, then I should be swinging my 7-iron about 85 mph instead of 75 mph.
So what’s the big deal? Let’s do some more math. If I swing a 7-iron 10 mph faster with a 1.4 smash factor (about what my 7-iron is capable of), that gets me 14 mph more of ball speed. And each mph of extra ball speed with a 7-iron yields 1.3 to 1.5 more yards of carry. Taking the middle of that, 1.4, and multiplying it by 14 gets 19.6 yards.
That’s an extra 20 yards(!) potentially of carry. Or about two clubs in the bag. A massive difference. And it’s something you can easily take advantage of if you aren’t already.
Dr. Sasho Mackenzie does slightly different math to arrive at a similar answer. He says your maximum 7-iron speed multiplied by 1.18 should equal your "expected driver swing." Again, using me as an
How do you get your iron speeds up?
Two words: Swing faster. No, really, that’s all you need to do. But obviously, you need to incorporate this into your practice sessions before going out on the course.
I’ve talked a lot about speed training, whether it’s with the Stack System or hitting drivers at max speeds at the range or simulator. But I had never thought about speed training with my irons until now. Because like with a driver, you need to teach yourself how to make good contact while swinging faster.
So what I’ve started to do with some practice sessions is when I go through my bag, I hit five to 10 balls with a certain club and then hit five with maximum effort before going to the next club.
I don’t track it as closely as I do with my driver by recording every shot during those sessions, but I know what my peak speeds are and I try to beat them just like I would with the driver. Here was one particular rip recently at COR Performance Golf in Armonk that I was proud of:
That’s a 90-mph 7-iron, or 20 percent faster than what I was swinging before. And that speed was already in the tank. I just had to use the full tank. Of course, you’re not always going to want to swing this hard, especially with your irons, but this kind of practice raises your floor. My new normal 7-iron swings are usually around 85 mph now so I don’t have to imagine hitting my irons farther now because I am. And having more firepower on the course lets you attack greens with shorter clubs that you're more comfortable swinging.
Mackenzie, one of the co-founders of the Stack System, does some slightly more complicated math to arrive at similar numbers. Through his research, he concluded that someone's max 7-iron speed (As always, make sure you're completely warmed up before you start swinging at max effort!) multiplied by 1.18—what he found is the average 7-iron-to-driver-ratio—equals their "expected driver speed." So my 90 mph with the 7-iron becomes 106.2 with the driver, which is in line with what I'm shooting for.
The best part? If you’ve already put in the speed work with the driver, then this should be easy. You already know you’re capable of swinging your irons faster if you’re not within 20 mph with your 7-iron. It’s just a matter of getting comfortable swinging faster. Remember, though, that this is a general rule. MacKenzie notes certain mechanics—in particular, regarding how you release the club—make some golfers more likely to swing the driver proportionally faster.
Anyway, next time you’re at the simulator—or at the range with a radar—compare your 7-iron club speed to that of your driver. And remember the “Rule of 20.” It may lead to the easiest 10-to-20 yards you've ever found.