Some things are worth a refresher. It’s been over a year since we talked about smash factor. Foresight call this Efficiency – it’s the same thing. Let’s give it a quick review.

It sounds like it measures how hard a player hits a shot. In a way, it is. It’s more an indicator of how solid a player hit a shot.

Smash Factor is a ratio of clubhead speed to ball speed. In other words, it looks at “what you put in” (clubhead speed) and compares it to “what you got out” (ball speed). We’ll get into what’s a good number in a bit, but for now, let’s dive into the nuances of this spec and why it’s important. 

When I am working with a player, this is the first number I look at after watching the ball in the air. I look at it after every shot. Why?? The higher the number, the more ball speed the player got relative to his clubhead speed. The higher the number, the more solidly the shot was struck. The more solid the shot, obviously, this tells us a good measure of the players potential – important for trying to fit a player for new equipment (or for teaching a player during a lesson). Once I see the smash factor for a shot, I can dive deeper to find out WHY it went up or down. Did the clubhead speed go up and the ball speed went up? Clubhead speed went down and ball speed was unchanged? Any combination will produce a different number. 

So what’s a good number? I always love it when a player says “what should my swing speed be?”, “how far should I hit my 7 iron?” or “is that good for someone my age?”. The answers are relevant to this discussion. The golf ball doesn’t care about any of that. The golf ball only cares about how fast is it traveling when it leaves the clubface. Other factors will influence distance, but not by as much as you might think. For example, a 100 MPH ball speed with an average 7 iron will go about 155 yards, while a 100 mph ball speed with an average driver will go about 160 yards. The difference is largely due to the spin generated by the two different clubheads. The bottom line is this 100 MPH ball speeds will go 155-160 yards. Sometimes we feel like we have to re-learn the entire equation. The reality is, you don’t!! So what can we do to help this as a fitter or instructor?

Let’s dive in – backwards. Smash Factor is a ratio of clubhead speed to ball speed. Dividing the ball speed by the clubhead speed, we get a number that will almost always be between 1.00 and 1.55. Think of this this way – a driver swing that has a 100 MPH clubhead speed that delivers a ball speed of 150 MPH will give a smash factor of 1.50. Simple, right? So, why the range (1.00 to 1.55)? Because as you add loft to the club head, the strike is more “glancing”, and the resulting ball speed will not go as high. In other words, with a 7 iron, we strive for a 1.35 smash factor. A lob wedge will be closer to 1.00. Filling in the blanks, the optimal numbers will be different for each club (there isn’t a standard for all irons, and a different standard for hybrids, etc.). If you have a player hitting a 5 iron, that smash factor might be closer to 1.40, while a 9 iron may be closer to 1.25. A 3 wood should be in the 1.45 range. These are for IDEAL strikes. 

Can a number go above the “ideal number”? YES. Here’s how. Certain impact conditions will generate very efficient energy transfer. Upward attack angles and slightly closed club faces (a low spinning, high draw), will tend to have disproportionately high ball speeds. Modern equipment can also have the same effect. Many irons are now hollow with tungsten inside the head, and this will produce some spring like effect off the clubface which can produce a 1.4+ smash factor off the face of a 7 iron. Traditional blade style irons will tend to not get much above the traditional numbers. Fairway woods (which are made like a mini-driver nowadays) will also get up there as well. 

Is it a ball speed “Free-for-all”? Ha. no. The USGA used to only test driver clubheads for spring like effect. Now they test anything the is 25* of loft or stronger. Yes, your new 5 iron gets tested to ensure it’s face is not too hot.

If you understand most of this so far, the important question is “How does one impact the other”? An increase in clubhead speed of 1 MPH will typically get about 1.5 MPH in ball speed. Typically for every 1 MPH increase in ball speed, a player will see 2.5 – 3 yards of additional carry. Many players already swing the club at a speed that is appropriate for them, so adding a ton of speed is not an option, or a LOT of work if they are physically cable of doing so. That new driver though… can that help me? It may!! there may be some additional things we can tweak to help tick the numbers higher as well. Read on.

Let’s assume a 100 MPH swing speed for each of these examples below. 

Current driver produces 146 MPH ball speed. This will get roughly 240 yards of carry.

Say a new driver gets 150 MPH ball speed. That will bump it to 250 yards of carry.

The smash factor jumped from 1.46 to 1.50 and the player got 10 yards. That’s a rounding error for cryin’ out loud… That additional 10 yards is the difference between carrying a FW bunker or not, getting a clean shot around the corner of a dogleg, etc. All of this, and at the same club head speed. Interesting…

Same player from above with the 100 MPH clubhead speed. Let’s assume he’s a 1.46 smash factor with his current club and we give him a new club and he get’s up to 1.48. He gained 2 MPH in ball speed and 5 yards. Great!!, but you’re not done yet. The real fitter will try to determine WHY isn’t he getting 1.50 or higher. In this example, he will be very close to being very good. Impact position will tell us why he isn’t getting all the ball speed he deserves. Often, I will try a shorter shaft to hone in on dead center strikes. Center contact will produce the highest ball speeds for EVERY clubhead speed. With a shorter shaft, club head speed can decrease by 1 MPH or so, but ball speeds often increase above previous levels due to better centeredness of contact. 

Last thing. The awkward conversation. “I just want to hit my driver 200 yards like I did last year.” A 70 MPH driver clubhead speed with a perfect 1.50 Smash Factor produces a Ball Speed of 105 MPH (70 X 1.5 = 105). From above, this shot is not going more than 170 yards. The reality is, a 200 yard drive with a 70 MPH club head speed is mathematically impossible unless it’s at elevation, downwind, or some pavement is involved. Could you help though? IF the contact is good, and he already maximizes the performance with the standard length, you could try to go to a longer length. That can add some clubhead speed, and ball speed IF the contact is still good. Might be worth a try. Look at the smash factor with the longer club – if it holds steady, look at the clubhead speed and ball speed numbers. If both are climbing and the ball still goes straight, it might be a combination to consider…

Remember, Ball speed makes ball go far, not clubhead speed. The combination of the two optimizes a players potential. Smash Factor tells you how close you are to achieving that. Try any of these things on your launch monitor and see how the performance changes as you make different swings. Get comfortable looking at smash factor data and integrate it into your fitting or teaching process. To me, it’s the gold standard of specs since it tells you if a shot is worth looking at or night well before it even get’s to it’s apex. A time saver for sure, but more importantly, it tells you if you’re on the right track in way fewer swings. 

I hope this helps!! Happy Fitting.