Thoughts on smash Factor, shaft flex and hitting

Some unstructured reflections on smash factor, shaft flex and hitting:

I have been looking for a driver replacement lately and have been on two differnet launch monitors. The first gave me a smash factor of 1.5, a swing speed of 93-99 and an ridiculous carry distance of 275-280 yards which I only get in my dreams or perhaps with an extreme wind from behind… The swing speed was around what I was expecting- 95 to 100 on a day where I only hit it half solid.

Today I was on another launch monitor. I was there to find a replacement shaft to my old driver that just broke a couple of weeks ago. I was using a great shaft that is no longer in production. The 65g version of the Harrison Tour 2.5 series. Very stable shafts, very low torque. I didn’t realise how stiff those shafts were until today…

The monitor took a picture of the ball three times while it was launched. That one seemed to give the right carry distance. Around 240. I was however quite surprised to see that the swing speed was in the low 90’s. And also to see a smash factor 1.6. Isn’t 1.5 supposed to be the max? I guess that’s for the golfers who plays “the clubhead is disconnected from the shaft at impact” game…

Since I’m a short hitter they expect me to fit in somewhere between regular and stiff. I know that I need a shaft that is stiffer than my swing speed would indicate. But since I’m a lefty there’s limited shaft selections to try so it’s usually different “stiff” shafts. I found a stiff Fujikura shaft that worked pretty well and I was just about go for it. I had the fitter measure this shaft. It flexed at 247 cpm. Then I had him measure the flex of my DIY 3 and 5 wood since they have worked well for several years, and besides have the same shaft as my before this favourite driver. The woods checked in at 268 and 272 - which according to the fitter would correspond to a driver flex around 258-260. Add to that an exceptional lew torque and you’re looking at something that is a lot stiffer than “stiff”. I ended up ordering the x stiff version of the Fujikura shaft without even trying it. I have never tried a club that is so stiff that I can’t hit it, but I’ve tried several that are so weak that it feels like swinging a snake. I can’t wait to get my hands on a driver that doesn’t give in :mrgreen:

I also measured an old hybrid that I have lying around that feels a tad stiff too, but gives good and very precise distance. The cpm on that one was 192. Seems to me like it’s sound advice to go with the stiffest flex you can handle.

What’s this got to do with hitting?

There is a lot more force than swing speed alone that gets my ball airborn when I hit the ball reasonably well. And I think my recent discoveries about smash factor and shaft flex confirms that the clubhead is pretty far from just freewheeling through impact in my case anyway.

If you really work the club hard through the ball it should show up in the smash factor and ABS’ers should have a higher smash factor than other golfers. And certainly stiffer shafts.

Sorry but there is no smash factor above 1.5 with drivers - unless the machine is broken or you use a hot face. And it decreases with higher lofted clubs.
There are some occassions where guys have 1.51- 1.53 - but that was the the absolute max i´ve ever read about - and those guys who had above 1.5 were bombers.

The PGA-tour average smash factor is 1.48 - for the LPGA its even lower.
If you are intrested in reading up on this - Brian Manzella and Richie3Jack wrote articles about this topic.

First you’re saying that the highest smash factor for drivers is 1.5 and then you refer someone that goes slightly higher. Either there is an upper limit or there isn’t. You can’t have it both ways.

I’ll make it easy for you: Factors outside the clubhead and ball makes a difference. Shaft mass, shaft stiffness, the power you apply to the club through impact - these factors make a difference. I have read a few of the smash factor explanations out there, but they all have serious flaws since they don’t address these factors properly.

I can’t rule out that two different monitors I’ve been on both were wrong. But I have another theory: I get a high smash factor because I have moderate swing speed combined with more than average lag pressure through impact. If I had a better release the smash factor would go down even if I maintained the same effort through impact.

From Trackman:

A way to produce a higher smash factor would be to thin it - still get lots of speed on the ball but have very very little spin - i´m not sure if thats something somebody want to achieve.

This is why most launch monitors are junk. Although smash factor is probably one of the figures that all launch monitors…even Trackman and FlightScope, have difficulty with making precise measurements and calculations.

I highly doubt your face is ‘hot’ and it’s almost assuredly due to a faulty launch monitor.

I believe the highest smash factor you can have is 1.53 and that is with a driver. But that’s very rare. If you crush one and hit up on it, you may get to 1.50 or so, but usually good strikes are about 1.48.


I think the 1.6 reading was too high too. My guess is that the subject monitor systematically measured the swing speed too low and therefore produced smash factor figures that was too high.

My smash factor readings was nevertheless systematically high compared to what was regarded as good figures on that monitor. This was part of a regular driver fitting session at a professional club fitter in his own shop and he was in charge of the session.

My point is the if you apply more lag pressure through impact and / or manage to increase the effective mass - the smash factor will rise. I can feel the difference in my hands. There’s just more impact resistance there on the best shots. Resistance of the right kind. The difference showed up on the launch monitor. And it shows up on the course as well.

I would agree with that. I would like to know what your realistic carry distances are, though. I swing around 103-105 and carry the ball over 270 maybe once every 8 rounds.

The carry was 240 and change on the second launc monitor. I think that is a very realistic figure. Clubhead speed was around 93 and ball speed maxed at around 150. I trust the ball speed on this monitor. It was based on photographic evidence. I was hitting the ball pretty well and I was expecting the clubhead speed to be around 100.

The carry distances I got on the first monitor was seriously flawed. When I said “crazy” carry I meant it literally. The swing speed was between 95-99 which seemed appropriate and ball speed was max 150 mph that day as well. This vas a very different type of monitor.

The biggest surprise to me and perhaps the most useful info I got from the fitting was that my diy 3 and 5 wood which I love to hit had flex that was close to an x stiff.

Here’s some ‘carry efficiency’ stats from 2010 season on

Mark Wilson was #2 in carry efficency and average 106 mph of clubhead speed and his average carry was 265 yards, which gives him a carry efficiency of 2.482. His highest recording was 2.774.


Carry efficiency?

What could this possibly have to do with positioning the ball into the correct part of a fairway to open up the green for the next shot? What about wind and shot shape? Are we drawing this around a corner into the wind? A low runner? Hi down wind? I don’t understand what people are striving for here? Where is the golf in this?

I guess it’s a statistic that nobody really knows what to do about. Eventually, hashed up numbers get so hashed up that they are meaningless. If the people selling you those numbers are good enough salesmen, eventually you get blinded by the “science.” Even less frequently, let’s say once every seventy years or so, those salesmen using hashed up numbers are CEOs and bankers and everyone gets the shaft…tipped x-100s.

Yet, still, after all we’ve been through the last five years, we hang on the “economic forecast” that is created by people who will make money with it–so long as it is what we want to hear–all the while with the implicit understanding that there is no obligation on the part of the forecaster to be even remotely accurate, or any consequences for the forecaster if it is not.

Sorry, back to golf. What are you supposed to do with these hashed up numbers? I used to like this type of stuff because I’m a smart guy and I really like to understand things on a fundamental level. Now, I’m trying my hardest to get as mind-numbingly dumb on the golf course as possible.

Forgot who said this…maybe Hagen…but it went something like:

“You don’t have to be stupid to play this game, but it helps” :laughing:

That’s priceless. I’m really starting to appreciate this more and more.

RR wrote:

That’s great. One of the very top guys over the decades in our group might fall into this category. I definitely wouldn’t say he’s stupid, but he certainly doesn’t overthink stuff. And he’s never in trouble.