"you have to compress the ball!"

[baldguy]

I have a bit of trouble wrapping my brain around a couple of concepts that people throw around with regards to the golf swing. I studied physics quite a bit in school, and I'm an engineer by trade. Although my profession deals more with the electrical and computery type stuff, the concept of building and designing architecturally sound things is not really any different from the mechanical world to the electronic one. Different figures and such, but many shared concepts... I digress. My point is that my brain naturally wants numbers and figures to line up and make sense. The idea of golf ball compression, at least the way I see it used most commonly, does not make sense to me.

Physically speaking, a given golf ball should compress a given amount based on how much force is applied. Some balls will compress more easily, some less, etc. Golf clubs generally have angled (lofted) faces, so the blow will almost always be a glancing one. Glancing blows will apply some force in the forward direction and some will essentially be transferred to the surface (there are diminishing returns based on the materials) in the form of friction. More loft means a bit less forward direction, a bit more friction. Friction creates spin. Dynamic loft (a.k.a. spin loft) is a term that refers to the actual angle of the club face at impact. It is computed by adding the angle of attack to the natural loft of the club and then subtracting any forward shaft lean (at least this last part should be, but sometimes it gets left out of the equation for some reason). These facts are not the question, but I list them as a basis for discussion.

So, on to "compression". I hear and read people say things like "you have to hit down on the ball to compress it." Hitting down on the ball is simply the act of striking the ball during the downward part of the swing. There is exactly one thing that hitting down on the ball *really* does - it de-lofts the club. De-lofting is a simple way of saying "decreasing the dynamic loft by presenting a negative angle of attack." So, assuming a constant swing speed, any iron within a set will hit the same distance and compress the ball the same amount as long as the dynamic loft is the same. Someone actually once told me that compressing the ball means squeezing it between the club face and the ground for an instant, which of course is nonsense because the friction with the ground would bleed off so much energy that the ball flight would be negatively impacted, not positively.

We always tell people they have to hit down and they have to "compress the ball", but... the golf ball is *always* compressed at least a little bit when it is struck with any amount of force. The only way to compress it more is to either apply more total force (i.e. swing the club faster), or to change the angle that the clubface strikes the ball and therefore apply more of the given amount of force to forward movement and less to friction. When we say that someone is "hitting down on the ball" what they are actually doing is hitting it with less loft. Less loft means more compression and less backspin, so of course the ball with fly farther... just not as high and with less backspin. Simple physics. To put it another way, if one golfer is "compressing the ball better" and "hitting down better" than another golfer with the same swing speed, then what he is really doing is hitting his 7 iron with the same trajectory, spin, and distance (and therefore the same green-holding ability) that the other golfer hits his 6 or his 5.

Why is it considered such a good thing to turn a 7 iron into a 6 iron or even a 5 iron? Yes, the ball goes farther with that given club and swing speed, but it doesn't land as softly... why is this considered to be such a good thing? I'm not saying it's a *bad* thing necessarily, but at times it seems like this is treated like the holy grail of ball striking when in reality it's just de-lofting the golf club. People strive and toil to get that perfect "hitting down and compressing" move, when they could just go up a club and get the exact same result.

I posted this in Freddie's section because I'm hoping that his knowledge of the golf swing can help fill in some missing piece of information that I just don't have. I am pretty sure I understand the physics of it, and I don't think there is any way to get around the laws of physics, but if I *am* missing something, I definitely would love to be enlightened. Thanks in advance!

 

[SaffaClint]

Great question and I can't wait to hear the array of answers that'll surely follow.

 

[russtopher]

Here's my relative noob, completely unscientific take on one of the reasons that golfers "need to compress the ball" instruction/statement is so widely used. A lot of people, when they're starting out, feel like they need to help the ball into the air, leading to a flip. By telling golfers that they need to compress the ball, they're already getting in the mindset of hitting the ball on the downward part of the swing arc, and NOT making a conscious decision to attempt to help the ball up, or flip at it.

 

[cbill]

Baldguy: Bravo!!!

For many years now I have asked myself the same questions, and wrestled with these same thoughts. My general question was: Does hitting into the ground really make the ball travel farther, or provide any other real benefit?

The reason for my questions was simply a matter of whether it would be worth the risk of damage to my wrists and shoulders that could occur from continually striking the relatively dry, hard rocky soils common to the area where I live.

Not wanting to risk unnecessary damage to my body, I decided to be a picker, rather than swinging into the ground.

There are exceptions, such as when I have a bad lie (divot, etc.), or when the ground is soft, and I want additional backspin; but those occasions are rare.

Personally, I have never regretted my decision to become a "picker". I was 55 when I started playing golf and am still able to play a pretty good round at age 75, due in part, to reasonably good health. Also, as a picker, I can still practice for extended periods on mats, without irritating my shoulders, wrists, or hands.

One of the best benefit of being a "picker" is the good feeling I have when I walk away from the course knowing I am leaving it in the best possible condition for the players behind me.

Obviously I very much enjoyed you discussion. Thanks!

 

[blugold]

Since every iron has a different loft, I would think achieving the same loft between a 6 and a 7 iron at impact would be hard to do. Don't forget that shaft length plays a part as well.

 

[Jericho]

Hitting down is really just a euphemism for "forward shaft lean". On the downswing, at some point the wrist cannot physically hold the angle any further and the club is "released" from the wrist hinge. Hitting the ball in the moments after wrist angle is released is imperative to achieve maximum distance. This, I believe, you already understand so your question is "why do people instruct others to hit down?" Because while your physics is correct, you must remember that in the real world of application, possible and likely must be taken into account. Is it possible for a picker or someone to technically swing level or up to achieve the same feeling of "compression" and distance? Yes, but being able to delay the wrist unhinging that little extra fraction is not likely. That is why pickers that hit the ball far (Greg Norman) are few and far between.

 

[BamBooBender]

Good thread! I think your assessment is spot on, along with the "forward leaning shaft" that Jericho brought up, from what I understand that helps produce better ball speed through less deflection.

 

[Hawk]

Interesting thoughts, but I'm not sure I'm following what you're asking. Hitting the ball with a downward traveling path is really the only way to ensure consistency. Obviously one could be too steep, but the alternative (not hitting down on the ball) introduces a ton of potential misses and is terribly difficult to time. It actually introduces less spin as well, though launch goes up quite a bit. I just know this because it's a swing fault I've dealt with and have seen the results on a launch monitor.

 

[baldguy]

my questions are really about how hitting down on the ball affects ball compression, not about whether one should hit down or not. I get that it provides more room for error. What I'm asking is why we seem to value de-lofting as a thing all unto itself instead of just how it relates to consistency. Statements like "if you really want to get some good compression, do this..." give the impression that more compression is better. Why? Just because it goes farther?

disclaimer: I do hit down on the ball, with a measured 11-12* of consistent forward shaft lean. That's just how my swing is. I'm not trying to justify my personal style, I'm asking a theoretical question.

 

[capt.dru]

Dont worry about it. Just hit the ball!

 

[blugold]

my questions are really about how hitting down on the ball affects ball compression, not about whether one should hit down or not. I get that it provides more room for error. What I'm asking is why we seem to value de-lofting as a thing all unto itself instead of just how it relates to consistency. Statements like "if you really want to get some good compression, do this..." give the impression that more compression is better. Why? Just because it goes farther?

disclaimer: I do hit down on the ball, with a measured 11-12* of consistent forward shaft lean. That's just how my swing is. I'm not trying to justify my personal style, I'm asking a theoretical question.

My understanding is that by hitting down on the ball, delofting the iron, and compressing the golf ball does a few things. First, it is easier to time and is much easier than the opposite. Second, it creates distance. Thirdly, impacts just as much spin or more than not delofting the iron at impact. That is just my understanding.

 

[drp3434]

Yeah the ball always compresses, but when you hit down on it you are using the ground to your advantage I believe and compressing it more than if you pick it off. I would think you're "pinching" the ball in a way, which creates more backspin, ball speed, and consistency.

Put a pencil on your desktop and pinch down on it with a finger. That sucker will launch!

 

[golf4life]

Yeah the ball always compresses, but when you hit down on it you are using the ground to your advantage I believe and compressing it more than if you pick it off. I would think you're "pinching" the ball in a way, which creates more backspin, ball speed, and consistency.

Put a pencil on your desktop and pinch down on it with a finger. That sucker will launch!

This is a commonly held belief that isn't actually what really happens. I've seen videos on youtube of an iron making contact with a ball and the ball immediately ascends without compressing into the ground. Its just laws of physics at work as the loft on the club is greater than the descending angle into the ball.

I believe the "compress it" directive is really misnamed in this case. I believe the right description for what people are trying to communicate is simply hit the ball before the bottom of the swing arc. The "compression" swing thought might be to picture yourself compressing the ball between the club and the ground, although in reality that's never actually physically happening. But if that thought helps people make better ball first contact, then great.

 

[buckbug]

I am impressed with the science and logic.

 

[drp3434]

This is a commonly held belief that isn't actually what really happens. I've seen videos on youtube of an iron making contact with a ball and the ball immediately ascends without compressing into the ground. Its just laws of physics at work as the loft on the club is greater than the descending angle into the ball.

I believe the "compress it" directive is really misnamed in this case. I believe the right description for what people are trying to communicate is simply hit the ball before the bottom of the swing arc. The "compression" swing thought might be to picture yourself compressing the ball between the club and the ground, although in reality that's never actually physically happening. But if that thought helps people make better ball first contact, then great.

Sounds good though doesn't it?

 

[-CRW-]

Here's my relative noob, completely unscientific take on one of the reasons that golfers "need to compress the ball" instruction/statement is so widely used. A lot of people, when they're starting out, feel like they need to help the ball into the air, leading to a flip. By telling golfers that they need to compress the ball, they're already getting in the mindset of hitting the ball on the downward part of the swing arc, and NOT making a conscious decision to attempt to help the ball up, or flip at it.

I think this statement sums it up. Everyone learns differently, and this term is thrown out not as a scientific truth, but as a means for some people's brains to understand the intended action.

As someone who takes lessons weekly, I can say there have been many times when I can't make the coaches desired change until he describes it in several different ways. Some phrases/terms don't relate to me, and then one expressing the coaches same idea in a different way just clicks.

Just an example, but saying "just swing the club and let the ball get in the way" translated to a "picker"/"scooper" type swing to me instead as opposed to a ball/grass/ground compression swing.

 

[baldguy]

This is a commonly held belief that isn't actually what really happens. I've seen videos on youtube of an iron making contact with a ball and the ball immediately ascends without compressing into the ground. Its just laws of physics at work as the loft on the club is greater than the descending angle into the ball.

I believe the "compress it" directive is really misnamed in this case. I believe the right description for what people are trying to communicate is simply hit the ball before the bottom of the swing arc. The "compression" swing thought might be to picture yourself compressing the ball between the club and the ground, although in reality that's never actually physically happening. But if that thought helps people make better ball first contact, then great.

I agree, and I think it has something to do with the feeling of ball-then-ground contact. My theory is that the impact of the ball is muted because the impact with the ground immediately following "smooths out" the vibrations. That results in a feeling of a more pure hit (on average) than picking it. I've experienced the sensation of both and they are definitely different, but I can only guess about the "why" without any sort of precision equipment to measure it.

Ball-first contact is essential to ensuring that all of the energy of the club is transferred to the ball and not reduced by the ground. I asked the question just so I can better understand *why* people talk about higher compression as something to strive for. de-lofting solely for the purpose of generating more distance seems odd to me. If this methodology is designed to promote ball-first contact then it can't be a bad thing. I think, like golf4life suggested, that it is simply a matter of terms being very commonly misused, and therefore occasionally misapplied by some.

 

[arydolphin]

my questions are really about how hitting down on the ball affects ball compression, not about whether one should hit down or not. I get that it provides more room for error. What I'm asking is why we seem to value de-lofting as a thing all unto itself instead of just how it relates to consistency. Statements like "if you really want to get some good compression, do this..." give the impression that more compression is better. Why? Just because it goes farther?

disclaimer: I do hit down on the ball, with a measured 11-12* of consistent forward shaft lean. That's just how my swing is. I'm not trying to justify my personal style, I'm asking a theoretical question.

Curious how you know what your shaft lean is? Have you measured it via video, or are you just going off of launch angle vs. the loft on the club? I don't have to time to expand a lot further on it, but for now, I'll say that doing the latter is not a great way of estimating shaft lean. FWIW, Martin Chuck (inventor of the Tour Striker) says that you can hit his club pretty well with 4 degrees of forward shaft lean and a 4 degree downward angle of attack.

Also, as others have mentioned, the objective should not be solely to hit down on the ball. Having the club traveling downward in the forward swing is already built into the swing unless the low point of the club is occurring behind the ball. Having your hands in front of the ball at impact does deloft the club, and allows for more energy transfer into the ball. More ball speed = more distance. If you're more efficient with your swing and can generate more ball speed, then you go from hitting a 6 iron from 150 out to hitting an 7 iron from 150 out. I'm paraphrasing, but you said that it really doesn't matter if one person hits a 7 iron while another person hits a 6 iron. What you didn't mention is that the 7 iron is shorter in club length than the 6 iron, and thus makes it easier to hit than a 7 iron.

Another thing: if the low point of the swing is at the ball or ahead of the ball, hitting down on the ball is ALREADY built into the swing, a person doesn't have to do anything additional to get the club to travel downward at impact. Plus, research has shown than forward shaft lean paired with a shallow downward angle of attack produces the most "compression" of a ball, meaning the most spin on a ball. That's why the tour pros can generate tons of spin on that 50 yard pitch shot where the ball comes in low and they barely take any divot during the strike, as opposed to the old-school thought that you had to get steep and hit way down on the ball and produce craters for divots to get spin. Focus on getting the low point (aka divot) in front of the ball with your hands ahead of the ball at impact, and you will be hitting down on it, guaranteed.

 

[baldguy]

the number I stated has been measured by multiple devices designed to measure such things, Swingbyte and SkyPro for example. I wasn't bragging about it, I don't know if that number is good or bad, I was just stating the fact.

the above is a good example of what I'm talking about though... you use the term compression to mean something different from what other people use it to mean, which is different still from other definitions. Compression by itself does not necessarily mean more spin. if you get more compression at the exact same dynamic loft, you would generate more spin, up to the limits of the ball involved. That happens because the ball stays in contact with the club face for a longer period of time so more friction is able to be imparted. However, the reduction in dynamic loft offsets this effect by reducing the angle at which the frictional force is applied. In other words, the maximum potential for friction is decreased, but the efficiency is increased. The result could be less, the same, or more depending on the ball, the club face, the grooves, the golfer, etc. But, by itself compression does not equal spin. That can be easily proven by looking at the actual compression on a golf ball on a high-speed camera from a driver versus a wedge. The driver will always compress the ball significantly more, but the wedge will always generate significantly more spin.

If you re-read my previous posts in this thread, I think you'll see that I agree about the hows and whys of hitting down on the ball and making contact with the ball first. That's not what this thread was intended for though. I'm trying to get to the root of why people champion more compression for a given shot.

 

[WardF]

I don't think any of the good instructors out there are trying to get you to increase distance through de-lofting though. Just maximizing your smash factor transferring the maximum speed you can from the club to the ball at the correct angle of attack. the iron and wedge game is about distance control even more than raw distance.

Edit: to Clarify further. Assuming you have a determined spin loft (combo of the angle of attack and the actual club loft) and a given club head speed and make center contact. --The correct instruction assuming these numbers are already optimized is NOT to hit more down on it to make it go further. The correct instruction for more distance in that scenario is increasing club head speed. Whether that is through better mechanics or using hips more etc--I don't think anyone is saying "hit down more" if there is already a good number there.

 

[BIGBALL]

Recent science, and with the inception of higher speed video, trackman, etc. has also shown the old idea of " Handle of the club way ahead of the ball at impact for compression" is in no way optimum. That was a thought from the Golf Machine book, which although had some good thoughts, etc, some of the science was flawed. Looking very closely at the vast majority of golfers on tour shows that at impact, the club is just about lined up with the hands at impact. Basically, the best players are pretty much hitting their clubs at their stated lofts. Brett's & Ary are spot on in what they had to say imo...

 

[Tadashi70]

How about we just swing the golf club?! Way too much thought going into something most can't feel anyway. Find a ball that you like. Get a swing you like and play golf.

Why so much over thinking goes into the game, I will never know. And yes it's ok to discuss but this goes beyond it and some will freeze over the ball as result.

Stance, posture, grip.......

 

[Jericho]

my questions are really about how hitting down on the ball affects ball compression, not about whether one should hit down or not. I get that it provides more room for error. What I'm asking is why we seem to value de-lofting as a thing all unto itself instead of just how it relates to consistency. Statements like "if you really want to get some good compression, do this..." give the impression that more compression is better. Why? Just because it goes farther?

disclaimer: I do hit down on the ball, with a measured 11-12* of consistent forward shaft lean. That's just how my swing is. I'm not trying to justify my personal style, I'm asking a theoretical question.

Why do we value de-lofting the club? Because it is a means to success.

1. "Compression" = solid contact
2. Solid contact requires forward shaft lean
3. Forward shaft lean (more or less) requires hitting down

De-lofting the is the result of hitting down, which results in forward shaft lean, which produces solid/consistent contact & distance.

To relate to your question, I don't believe we value de-lofting as a thing unto itself. De-lofting is a reaction as opposed to an action. We are seeking forward shaft lean and forward shaft lean just happens to de-loft the club. It's like saying you need big muscles to lift heavy objects....no, you need to be strong, to lift heavy objects and big muscles are just a result of being strong.

I think people are using the wrong terminology and you're being overly analytical

 

[dizzyg12]

There must be a science behind it and truth to it if every instructor says to get more
Compression and every ball manufacturer aims to get better compression


Sent from my iPhone using Tapatalk

 

[rollin]

How about we just swing the golf club?! Way too much thought going into something most can't feel anyway. Find a ball that you like. Get a swing you like and play golf.

Why so much over thinking goes into the game, I will never know. And yes it's ok to discuss but this goes beyond it and some will freeze over the ball as result.

Stance, posture, grip.......

I can understand what your saying but with due respect I think things like this are a bit different from the pressures one may put on onself with actual over doing of swing instruction.
Two different things imo. One being more of a ( "do this, do that, and this other thing, and dont forget about this too and then that there" ) over instructed type of thing LOL. And that is the stuff that can cause negative problems such as you are saying because its an over doing of instruction.

But I think info like this topic is a bit different. Even if it may be a lot to grasp I dont think it causes the same possible negative affect that one may experience with being over instructed. I find that understanding the science behind things in anything we do (work, sports, hobbys, whatever) is always beneficial.

Even just to understand (as mentioned in this topic) the truth about compressing the ball against the ground being a false statement is beneficial for one to find out and know about. Its much the same as one correctly understanding what swing path and face angle do. Or even those who always believed (and many out there still do) the ball spins forward with a driver which is a very common misguided belief. These and just about any other misunderstood facts are imo very beneficial to know. There is no denying that the more one understands corectly about anything even if it seems meaningless is all the better for it in the long run. Simply put, the better one can understand the science behind things the more things make sense. It can only have a positive effect imo. I dont feel this type of in-depth knowledge would put the same pressures on a swing like being over instructed may do.