Bryson DeChambeau

GreeBo · 11-07-2020 12:39PM

bren2001 wrote: »

At what point did I say any of that was negligible? I don't know if you're intentionally misunderstanding what I said about shaft bend or not but when you're doing a mathematical analysis at the point of impact, what has happened before is irrelevant. The bend is taken into account by the shape of the club at the point of impact. That's how shaft bend is taken into account in a simple model. My statement was relating to the deflection of the shaft in the moment before impact and the moment after. An infintely small amount of time. I don't believe the deflection that occurs due to the strike of the ball in this time-frame is a significant factor.

The model and mathematical analysis I've stated in this thread is solely to demonstrate that the weight of a player has an impact on distance. It is not a full model to actually calculate the distance a ball would travel. You would need a much more sophisticated model for that. Most likely a DAE.

I don't particularly want to waste my time talking to a brick wall. My only point is that the weight of a golfer impacts the distance a ball will travel. I am not saying what other factors are important.

It seems to me that you've accepted that weight does matter in a golf swing but you don't want to admit you are wrong and are now trying to twist your argument or move the goalposts. Very simply, do you now accept that the weight of a golfer does impact the distance a ball will travel? That's the only point I've been trying to convey.

No I don't.
I started saying the ball didn't care about anything other than impact, you started saying the golfers weight is relevant, I'm saying is not and you haven't been able to demonstrate anything to the contrary. I asked would iron Byron hit it further if you have it heavier and you ignored it. I asked various similar questions and you ignored them.

The ball is hit by the club and distance depends on the force, which is the mass times acceleration of the club. The same club at the same speed hits the ball the same distance.
Why is Rory longer than koepka with the same swing speed and 20kg lighter?

GreeBo · 11-07-2020 12:41PM

Henry Ford III wrote: »

Magnificent strawman. Simply outstanding.

Why does every other pro use different length irons?

I don't think anyone knows what point you are trying to make... Can you explain?

bren2001 · 11-07-2020 01:06PM

GreeBo wrote: »

No I don't.
I started saying the ball didn't care about anything other than impact, you started saying the golfers weight is relevant, I'm saying is not and you haven't been able to demonstrate anything to the contrary. I asked would iron Byron hit it further if you have it heavier and you ignored it. I asked various similar questions and you ignored them.

The ball is hit by the club and distance depends on the force, which is the mass times acceleration of the club. The same club at the same speed hits the ball the same distance.
Why is Rory longer than koepka with the same swing speed and 20kg lighter?

Right, here's an article titled "Are heavier baseball players better hitters? Basically, no, says physics". The conclusion is that heavier baseball players don't hit it further because their swing changes. The same is true for golfers . I have not disputed that and specifically stated earlier that "fat players typically won't perform well but if they had the exact same swing as a much lighter golfer. I would expect the fat golfer to hit it further". The point being, two players with the same swing but different weights will hit the ball different distances. That's the only point I'm trying to make.

You're claiming "the same club hitting the same ball at the same speed imparts the same force on the ball" and that "the club has no idea what mass is being used to swing it" i.e. the weight of the golfer has no impact on distance.

The article states: "It’s all about kinetic energy, the kind of energy used in motion. It’s described by the formula k = (1/2)mv2, where m is the mass of the system—here, the weight of the hitter and the bat—and v is the velocity, or speed, which here accounts for the movement of hitter and bat. "...."in theory, if a bigger guy is just as fast or strong as another guy, he should be able to hit the ball further" note: the weight of the batter is taken into account.

Towards the end of the article (3rd last paragraph) it states "If—and only if—players can keep their speed constant while making perfect contact with the ball on a perfectly hard bat, they would be able to hit the ball harder if they’re bigger" where bigger means heavier i.e. the weight of a baseball player impacts distance. I'm making the exact same point about golfers.

Can you either explain why a baseball players weight would matter but not a golfers or explain why researchers a Penn State University and I are incorrect?

https://qz.com/801738/why-are-baseball-players-fat/

Golf is my Game · 11-07-2020 01:12PM

With yere maths theres also the mistake in trying to make it to a static situation because it isnt. While the time the clubs in contact with the ball is very small and so intuitively we tend to think of it as an instant in fact the time the ball is in contact is very important and is a critical element in the pros getting their distance and spin on the ball. The ball is very elastic, and the club head slightly elastic. The acceleration/deceleration of the clubhead and what your swing timing is doing to it for the period of contact is crucial to the compression of the ball. the transfer of clubhead speed to ball speed, and to the spin put on it as a result. Swing timing that maximises the time the club is in contact with the ball is what allows top players put such back spin on the ball that they can control it on the green, even with short clubs where high clubhead speed is not required they can do it. Its a dynamic impact. Low level golf simply never get such spin on the ball to have the ball spin back on the green because they arent able to sustain the club head speed as it contacts the ball (they fool them selves sometimes that they do when a ball jumps back out of its pitch mark but that werent the spin).

Golf is my Game · 11-07-2020 01:17PM

Henry Ford III wrote: »

Magnificent strawman. Simply outstanding.

Why does every other pro use different length irons?

Because its the best way found over the years to get best gaps between the clubs by spreading the distance gained between them between a little loft change and a little length channge. Its a balanced compromise. You could do it with same length clubs like Bryson. Or you could do it with same loft on them all and change the length much more. Either works. A mix works best though top elite players with great club head speed as a result of their swings can nudge it towards the loft being the difference. Club golfer could more likely benefit the otherway. Put more loft on the club and make it longer. The ball will get in the air easier. But theyl find they run out of length in the irons then. But us hyrids from about 6 iron down and they would do well. Seniors and lads in the 20 handicaps range and so on. In fact they sort of being doing it for years anyway with 7 woods and the lokes of the 'gentlemans persuader' type clubs for decades even before hybrids were found to be a more easily hit low twenty degree club for the less skilled.

bren2001 · 11-07-2020 01:44PM

Golf is my Game wrote: »

With yere maths theres also the mistake in trying to make it to a static situation because it isnt. While the time the clubs in contact with the ball is very small and so intuitively we tend to think of it as an instant in fact the time the ball is in contact is very important and is a critical element in the pros getting their distance and spin on the ball. The ball is very elastic, and the club head slightly elastic. The acceleration/deceleration of the clubhead and what your swing timing is doing to it for the period of contact is crucial to the compression of the ball. the transfer of clubhead speed to ball speed, and to the spin put on it as a result. Swing timing that maximises the time the club is in contact with the ball is what allows top players put such back spin on the ball that they can control it on the green, even with short clubs where high clubhead speed is not required they can do it. Its a dynamic impact. Low level golf simply never get such spin on the ball to have the ball spin back on the green because they arent able to sustain the club head speed as it contacts the ball (they fool them selves sometimes that they do when a ball jumps back out of its pitch mark but that werent the spin).

Your point was that the weight of the golfer has no impact on the distance they can hit it. I've said if two golfers of different weight but all other variables are the same hit a golf ball at the same speed, with the same swing, at the same angle etc. the heavier golfer will hit it further. You stated this was incorrect and the only things to consider are loft and length (the later of which is incorrect).

If all variables are kept the same except for the golfers weight what you're saying wouldn't need to be taken into account to demonstrate that weight can impact distance.

I've stated that the static model was solely to demonstrate my point and nothing else. It would not be how I would estimate distance mathematically.

First Up · 11-07-2020 04:22PM

The ONLY factor affecting distance is the speed at which the club hits the ball. Fat golfers, thin golfers, light golfers, heavy golfers, tall golfers and short golfers will all hit the ball exactly the same distance if they hit it with the same clubhead speed.

The real question is how does a golfer's weight influence the clubhead speed they can generate. I don't think it does - but muscular strength might.

bren2001 · 11-07-2020 04:26PM

First Up wrote: »

The ONLY factor affecting distance is the speed at which the club hits the ball. Fat golfers, thin golfers, light golfers, heavy golfers, tall golfers and short golfers will all hit the ball exactly the same distance if they hit it with the same clubhead speed.

The real question is how does a golfer's weight influence the clubhead speed they can generate. I don't think it does - but muscular strength might.

Can you explain why a golfers weight doesn't effect distance but the linked article above shows that a baseball players weight effects distance? What is the fundamental difference? Why would a golfers weight not feature in the conservation of momentum or energy laws?

First Up · 11-07-2020 04:32PM

bren2001 wrote:

Can you explain why a golfers weight doesn't effect distance but the linked article above shows that a baseball players weight effects distance? What is the fundamental difference? Why would a golfers weight not feature in the conservation of momentum or energy laws?

Is there evidence that baseball players (or golfers) of different weights but the same swing speeds achieve different distance?

In any case, baseball is not a good comparison; a baseball is moving before being hit which is an important variable. A golf ball is static.

bren2001 · 11-07-2020 04:41PM

First Up wrote: »

Is there evidence that baseball players (or golfers) of different weights but the same swing speeds achieve different distance?

In any case, baseball is not a good comparison; a baseball is moving before being hit which is an important variable. A golf ball is static.

See the article here:
https://qz.com/801738/...aseball-players-fat/
Research by Penn State.

Yes there is a difference but why would the mass of the golfer be taken out in the kinetic energy calculation but not for the baseball player?

First Up · 11-07-2020 05:05PM

bren2001 wrote:

Yes there is a difference but why would the mass of the golfer be taken out in the kinetic energy calculation but not for the baseball player?

Weight is only a factor if it contributes to force, generating speed.

Weight on it's own is meaningless, unless it translates into strength, generating greater force (speed).

bren2001 · 11-07-2020 05:35PM

First Up wrote: »

Weight is only a factor if it contributes to force, generating speed.

Weight on it's own is meaningless, unless it translates into strength, generating greater force (speed).

The article I linked explains that weight is a factor in its own right for generating force through kinetic energy. Why would that be the case for baseball but not for golf?

The equation for kinetic energy is 0.5mv^2 and the article clearly states the baseballers weight is taken into account.

First Up · 11-07-2020 05:45PM

bren2001 wrote:

The article I linked explains that weight is a factor in its own right for generating force through kinetic energy. Why would that be the case for baseball but not for golf?

Baseball and golf are different (I have played both) but I still await evidence that a golfer weighing 120 kilos generating the same clubhead speed will hit a golf ball further than a golfer weighing 90 kilos.

bren2001 · 11-07-2020 06:03PM

First Up wrote: »

Baseball and golf are different (I have played both) but I still await evidence that a golfer weighing 120 kilos generating the same clubhead speed will hit a golf ball further than a golfer weighing 90 kilos.

They are different but at the end of the day, in both cases, you swing some form of stick/bat. If two baseball players have identical swings and clubs, the heavier one will generate more kinetic energy and hit the ball further. The article linked above explicitly states that. By logical extension, a golfer will generate more kinetic energy too. From an energy calculation perspective, there is little difference between a club and a bat. One is more stiff than the other. Can you please explain why this would not be the case? Why does the case of baseball not logically extend to golf?

In terms of a moving ball you mentioned earlier, it's irrelevant when calculating the kinetic energy of the player/bat/club before impact as it is independent of the ball.

Otherwise, can you please explain from a mathematical perspective why the weight of the golfer would not be taken into account in either the law of conservation of momentum or energy. If neither are applicable (they both are), can you please outline how you would calculate the initial ball speed from a kinematics perspective?

First Up · 11-07-2020 06:58PM

bren2001 wrote:

Otherwise, can you please explain from a mathematical perspective why the weight of the golfer would not be taken into account in either the law of conservation of momentum or energy. If neither are applicable (they both are), can you please outline how you would calculate the initial ball speed from a kinematics perspective?

I'd prefer to do it from a golfing perspective. There is plenty of data showing the direct relationship between clubhead speed and distance. None of it is qualified by the weight of the person generating it.

Golf is my Game · 11-07-2020 07:11PM

First Up wrote: »

I'd prefer to do it from a golfing perspective. There is plenty of data showing the direct relationship between clubhead speed and distance. None of it is qualified by the weight of the person generating it.

Yeh, if you go to your pro he never tells you you need to put on a few stone or has a scales in his teaching bay to see if youve got enough momentum through the ball. Not on TV. They dont comment on how players who lose weight like Bubba last year, or I though Rahm is looking slimmer this weekend, is going to lose distance and its going to cost him so he should go back on the pasta and cream cakes. Looking at the long hitters out there theres no correlation evident between the long lads and the short ones and their weight or even size. Rory is a small enough and light lad for example. Its all about speed.
How many yards would you say or would your equations back up, that a stone is worth to a tipical golfer ? Im an engineer too, but washing machines and dishwashers mainly rather than sports but, so still have a good feel for mechanics.

bren2001 · 11-07-2020 08:01PM

First Up wrote: »

I'd prefer to do it from a golfing perspective. There is plenty of data showing the direct relationship between clubhead speed and distance. None of it is qualified by the weight of the person generating it.

The relationship between clubhead speed and distance is well established. I'm not saying that's untrue. I'm sayi g the weight of a person makes a difference, that's all. That difference might be very very small.

Ok, from a golfing perspective, the kinetic energy before impact is 0.5mv^2, the m refers to the mass of the golf club and golfer. Why is that wrong?

bren2001 · 11-07-2020 08:16PM

Golf is my Game wrote: »

Yeh, if you go to your pro he never tells you you need to put on a few stone or has a scales in his teaching bay to see if youve got enough momentum through the ball. Not on TV. They dont comment on how players who lose weight like Bubba last year, or I though Rahm is looking slimmer this weekend, is going to lose distance and its going to cost him so he should go back on the pasta and cream cakes. Looking at the long hitters out there theres no correlation evident between the long lads and the short ones and their weight or even size. Rory is a small enough and light lad for example. Its all about speed.
How many yards would you say or would your equations back up, that a stone is worth to a tipical golfer ? Im an engineer too, but washing machines and dishwashers mainly rather than sports but, so still have a good feel for mechanics.

I never once suggested that adding weight is an advisable way to gain distance. It's clearly a silly way to do it. At no point in this did I say that.

You're original point was: "length the ball will travel is set by two characters of the club, the loft on the face and the length of it". That was incorrect, length is indirect. You've changed your position and now it's all about speed. I'm not arguing that this is the dominant characteristic.

However, you also said: "Weight, is incorrect. Speed and loft are all that matters.". This is wrong. Weight is a factor. How much does it contribute? I don't know and am not going to sit down and do the equations to give a definite answer. However, the weight of the golfer does impact distance. If it's true for baseball as outlined by Penn State researchers, it's true for golf.

How can Rory hit it so far? Very fast clubhead speed and he keeps the club square and on-line. If he weighed more and swung the club the same way, he'd hit it further. I've never stated weight is the dominant factor. It's not but it does contribute. That's all i've been saying.

You're an engineer, you've probably completed a course in mechanics or kinematics. Please explain how the weight of a golfer does not contribute to the kinetic energy at the point of impact. The formula being 0.5mv^2. Law of conservation of energy applies, the golf ball has no kinetic energy before impact. It has plenty after. Or, please explain why the findings of the following baseball study cannot be applied to golf:
https://qz.com/801738/why-are-baseball-players-fat/

Rippeditup · 11-07-2020 08:27PM

The thing with Bryson is the weight has been added with a very clear focus on overall strength while trying to not lose mobility, the strength/weight is being used heavily on how he loads up on the back swing and how he drives through on the left side on the downswing which is all based on coiling up his body and weight to get behind the hit..
with Rory he has insane mobility on the back swing getting his back, glutes and legs all coiled before releasing..
The swing speed is determined by the weight you load on the right side before driving the club through impact from the shift to the left side.. strength, weight, mobility and stability of the body all leads to more power...

I am no engineer but have been a long hitter of a ball since being a small kid and even today at 40 and been out for years would carry 290+ with big launches and I am no pro just understand body movement..
it’s like Olympic lifting, bigger lads will move more weight but vs body % will be nowhere near the smaller lads as the coil and power is better due to technique

Rory has exceptional technical ability which Bryson has also bit he has put in the raw power also with the weight gain to increase overall output

Golf is my Game · 11-07-2020 08:51PM

bren2001 wrote: »

The relationship between clubhead speed and distance is well established. I'm not saying that's untrue. I'm sayi g the weight of a person makes a difference, that's all. That difference might be very very small.

Ok, from a golfing perspective, the kinetic energy before impact is 0.5mv^2, the m refers to the mass of the golf club and golfer. Why is that wrong?

That you are counting all of the body of the golfer contributing to the mass in the 1/2mv2 equation. v is a vector with direction as well as magnitude. You are using all that v as if it were in the direction of the target. The 1/2mv2 component that resolves for the movement of the body of the golfer is neglectably zero since the v of the movement of the body as a mass is almost zero. The body itself simply isnt moving fast. And the remainder of the compnonent that is, is almost a zero sum, since mass of the body that is actually moving back (the left half for a right handed golfer) from the ball negates that which is moving toward the ball (the right side). Leaving no body momentum component that has any measureable contribution to energy transferred to the ball.

bren2001 · 11-07-2020 09:01PM

Golf is my Game wrote: »

That you are counting all of the body of the golfer contributing to the mass in the 1/2mv2 equation. v is a vector with direction as well as magnitude. You are using all that v as if it were in the direction of the target. The 1/2mv2 component that resolves for the movement of the body of the golfer is neglectably zero since the v of the movement of the body as a mass is almost zero. The body itself simply isnt moving fast. And the remainder of the compnonent that is, is almost a zero sum, since mass of the body that is actually moving back (the left half for a right handed golfer) from the ball negates that which is moving toward the ball (the right side). Leaving no body momentum component that has any measureable contribution to energy transferred to the ball.

I may be misreading what you are saying but any time I've hit a ball. My body is moving towards the target, not away from it. My centre of gravity is moving forward so my bodies momentum is forward. My body isn't static. My weight is shifting from my back foot to my front foot. It doesn't sum to zero, when you resolve the "force" it will be positive along the target line. My body is rotating. So v is not 0, it's a positive number.

Can you explain why this would be different for a baseball player as per the Penn State research linked above? Why would their kinetic energy not sum to zero?

If you're accepting that v is positive, then you accept that mass does have an effect. You just think it is negligible. We disagree there, I don't think it's negligible but I do think it's small. I don't see the point in arguing over semantics in that case.

I disagree with how you've done the above. You've effectively treated the club and body as two separate masses. You are joined at the hands and are one large mass. I don't think you can break it down like that nor have I ever seen it broken down like that.

First Up · 11-07-2020 09:12PM

bren2001 wrote:

Ok, from a golfing perspective, the kinetic energy before impact is 0.5mv^2, the m refers to the mass of the golf club and golfer. Why is that wrong?

The relationship between clubhead speed and distance is well documented and none of it mentions the weight of the golfer swinging the club.

Why not?

bren2001 · 11-07-2020 09:25PM

First Up wrote: »

The relationship between clubhead speed and distance is well documented and none of it mentions the weight of the golfer swinging the club.

Why not?

You'd have to ask the people who wrote those articles or conducted those studies. In the kinetic energy formula, its 0.5*m*v^2 so the clubhead speed will dominate the equation. Hence, most people would say weight isn't a factor. Which is mathematical untrue. That is my point. I believe if you took a golfer who weighed 0kg and a golfer who weighed 80kg hit the ball with the same swing, same ball, at the same speed etc. The 80kg golfer will hit it noticeably further. If the difference is 60kg to 80kg, the difference in length gets smaller and smaller to the point it is negligible.

I've answered your question. Can you please answer my question, why doesn't the research conducted by Penn State University on baseball players apply to golfers? Can you please explain why it doesn't apply, they are both humans swinging a club/bat. Mathematically, they are very similar.

Golf is my Game · 11-07-2020 09:45PM

bren2001 wrote: »

I may be misreading what you are saying but any time I've hit a ball. My body is moving towards the target, not away from it. My centre of gravity is moving forward so my bodies momentum is forward. My body isn't static. My weight is shifting from my back foot to my front foot. It doesn't sum to zero, when you resolve the "force" it will be positive along the target line. My body is rotating. So v is not 0, it's a positive number.

You should be moving back as you hit the ball if you want to emulate the pros. Rory's back move is credited with a small sling shot effect that gives him the big distance. Even without it, his head and shoulders are moving distinctly back as he hits the ball. Most golfers are. The forward weight transfer you describe happens in the trasnition and much of the down swing, but then either becomes stationary as the shoulders spin as the wrists straighen to the ball, or the upper torso moves back wards as above. But while this contradicts what you are saying, the main reason body motion doesnt matter is that at the point of impact is it spinning, not moving forward.

bren2001 wrote: »

Can you explain why this would be different for a baseball player as per the Penn State research linked above? Why would their kinetic energy not sum to zero?

I know nothing of the baseball swing. Lets keep it to golf. Does your interest in the baseball one say you cannot find supporting evidence on golf. Which is interesting.

bren2001 wrote: »

If you're accepting that v is positive, then you accept that mass does have an effect. You just think it is negligible. We disagree there, I don't think it's negligible but I do think it's small. I don't see the point in arguing over semantics in that case.

I disagree with how you've done the above. You've effectively treated the club and body as two separate masses. You are joined at the hands and are one large mass. I don't think you can break it down like that nor have I ever seen it broken down like that.

I am saying v is only purely positive for the club head. For the body much of it is negative : the upper torso and head moving backwards and the left side also rotating backwards. Much of the rest of the body has already moved from back to forward and is no longer moving forward, or forward at such a low speed that it has no relevant effect on the energy to transfer to the ball.

GreeBo · 11-07-2020 10:10PM

bren2001 wrote: »

See the article here:
https://qz.com/801738/...aseball-players-fat/
Research by Penn State.

Yes there is a difference but why would the mass of the golfer be taken out in the kinetic energy calculation but not for the baseball player?

Your article doesn't say so prove what you think it does.
Firstly "“in theory, if a bigger guy is just as fast or strong as another guy, he should be able to hit the ball further,” Karakolis says."

In theory, not fact.
Secondly they stress the point what matters to the ball is angular velocity, it doesn't matter how you generate this. They go on to state that a bigger guy needs more power to move at the same speed as a smaller guy.

Finally, the whole point all along has specifically been about all other factors being equal.
If you swing at 100mph then as long as you can resist the impact, or "remain stiff" in your article.l it doesn't matter what you weigh, it matters how much you can resist and get COR as close to 1, i.e. strength not mass or weight.

Golf differs from baseball at impact because golfers hands and forearms are passive compared to baseball where they are actively resisting.

First Up · 11-07-2020 10:20PM

bren2001 wrote:

I believe if you took a golfer who weighed 0kg and a golfer who weighed 80kg hit the ball with the same swing, same ball, at the same speed etc. The 80kg golfer will hit it noticeably further. If the difference is 60kg to 80kg, the difference in length gets smaller and smaller to the point it is negligible.

You will need more than belief to explain why none of the trackman and other calculations think a golfer's weight matters in the clubhead speed/distance charts

bren2001 wrote:

Can you please explain why it doesn't apply, they are both humans swinging a club/bat. Mathematically, they are very similar.

Some of it applies but much doesn't. Hitting a moving baseball needs incredible reflexes more than anything else. Distance is not the main objective - a home run is about 130 -140 yards.

bren2001 · 11-07-2020 10:55PM

Golf is my Game wrote: »

You should be moving back as you hit the ball if you want to emulate the pros. Rory's back move is credited with a small sling shot effect that gives him the big distance. Even without it, his head and shoulders are moving distinctly back as he hits the ball. Most golfers are. The forward weight transfer you describe happens in the trasnition and much of the down swing, but then either becomes stationary as the shoulders spin as the wrists straighen to the ball, or the upper torso moves back wards as above. But while this contradicts what you are saying, the main reason body motion doesnt matter is that at the point of impact is it spinning, not moving forward.

I know nothing of the baseball swing. Lets keep it to golf. Does your interest in the baseball one say you cannot find supporting evidence on golf. Which is interesting.

I am saying v is only purely positive for the club head. For the body much of it is negative : the upper torso and head moving backwards and the left side also rotating backwards. Much of the rest of the body has already moved from back to forward and is no longer moving forward, or forward at such a low speed that it has no relevant effect on the energy to transfer to the ball.

Is v negative or zero along the target line?

Your velocity is positive the swing plane. My golf coach doesnt tell me to lean away from the ball. I think your analysis is wrong.

You don't like the baseball analogy. Fine. I'll refer to the following golf study: "Changes in angular momentum during the golf swing and their association with club head speed" by Yoka Izumoto, Toshiyuki Kurihara, Takahiko Sato, Sumiaki Maeo, Takashi Sugiyama, Hiroaki Kanehisa & Tadao Isaka. Of particular note is Figure 2, "Changes in the angular momentum about the Z axis of the swing plane from the top of the backswing (0%) to the point of ball impact (100%):..."(b)body segments". At the point of impact, it is clear that the angular momentum of the sum of the body parts is positive along the z-axis of the swing plane.

Also note in (a), that the authors don't refer to it as the angular momentum of the club solely but the body-club system.

It's relatively clear and conclusive in the above peer-reviewed journal paper that the mass of the body contributes to distance. You can see from the numbers, it's actually relatively significant and in no way negligible.

bren2001 · 11-07-2020 11:09PM

GreeBo wrote: »

Your article doesn't say so prove what you think it does.
Firstly "in theory, if a bigger guy is just as fast or strong as another guy, he should be able to hit the ball further,” Karakolis says."

In theory, not fact.
Secondly they stress the point what matters to the ball is angular velocity, it doesn't matter how you generate this. They go on to state that a bigger guy needs more power to move at the same speed as a smaller guy.

Finally, the whole point all along has specifically been about all other factors being equal.
If you swing at 100mph then as long as you can resist the impact, or "remain stiff" in your article.l it doesn't matter what you weigh, it matters how much you can resist and get COR as close to 1, i.e. strength not mass or weight.

Golf differs from baseball at impact because golfers hands and forearms are passive compared to baseball where they are actively resisting.

In theory means theres a mathematical basis behind it. Are you saying the Penn State researchers mathematics is incorrect? If so, can you please point out where in the mathematics they have made a flaw in their assumptions? Why didn't the peer-review process pick this up? The purpose of peer-review is to ensure scientific integrity.

It is harder for a bigger guy to generate the power. I have not refuted this and been clear that the only variable I am considering is weight. All other variables are the same when comparing the two hypothetical golfers. In this case, the bigger guy will hit it further. The above research for a baseball confirms this: "in theory, if a bigger guy is just as fast or strong as another guy, he should be able to hit the ball further".

Can you please explain what passive means? The body of a golfer resists the golf ball. The golf ball "consumes" some of the kinetic energy. A baseball will just consume more as it's heavier and moving with a negative velocity. Both are actively resisting.

If in theory is not sufficient, then I don't believe you are willing to admit you are wrong.

Please also see Figure 2 of the following paper:
"Changes in angular momentum during the golf swing and their association with club head speed" by Yoka Izumoto, Toshiyuki Kurihara, Takahiko Sato, Sumiaki Maeo, Takashi Sugiyama, Hiroaki Kanehisa & Tadao Isaka.

They consider the body-club as one system and show the angular momentum of the club and body. The angular moment of the body is positive along the z-axis of the swing plane which clearly shows that the body has an impact on distance. If the angular momentum had no impact, then it's momentum is zero or would not be taken into account in the body-club system.

So far I have tried to demonstrate my point through:
The law of conservation of momentum.
Statics theory.
The law of conservation of energy.
A peer-reviewed paper relating to baseball.
A peer-reviewed paper relating to angular momentum in a golf swing.

Aside from the last, you have claimed none of the above are relevant yet have provided no mathematical reasoning as to why the mass of the golfer is not relevant. You have said that "in-theory" is not sufficient and not a fact, even though there is mathematical reasoning to back up this point. You have provided zero mathematical evidence to back up your position. Nor have you demonstrated that you have sufficient training or understanding of the laws of kinematics or those mentioned above to say how I am wrong or why I am wrong.

Based on the above, I believe you are either refusing to listen to another point of view or refuse to admit you are incorrect in your statement.

First Up · 12-07-2020 07:30AM

bren2001 wrote:

Based on the above, I believe you are either refusing to listen to another point of view or refuse to admit you are incorrect in your statement.

Have you any data that shows that any variable other than clubhead speed is a factor in how far a golf ball travels?

Golf is my Game · 12-07-2020 08:13AM

First Up wrote: »

Have you any data that shows that any variable other than clubhead speed is a factor in how far a golf ball travels?

Yes. There are the primary factors, of which speed is one. The others are loft, clubface cor, and the dynamic of the clubhead while in contact with the ball.

Then the secondary factors which is what the poster is referring too which are the things that affect clubhead speed and dynamic. These are club length, muscle, muscle speed, technique and timing which influence the effectiveness of turning muscle energy into clubhead speed, and its variation during impact. He right enough strictly in that weight if its muscle can make a club head go faster, but not in that mass which is the proper scientific term for weight from what Ive read, as hes using it here in itself contributes to hitting the ball further if its just a beer gut.

Bryson DeChambeau

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