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Post by imperfectgolfer on Nov 1, 2018 9:22:27 GMT -5
Dr Mann I have a suspicion that I know why Soloman (that 3D Director) mentioned the 'hands' being the major difference in clubhead speed for PGA men vs LPGA females. From what Dan Carraher said, Soloman works closely with Phil Cheetham , who in turn I've seen on videos with Chuck Evans . Chuck Evans produced this video below sometime ago , but I can imagine that Soloman has just reiterated what Mr Evans implied in that video but said 'Hands' instead of 'wrists' (Chuck Evans should maybe also have said forearms rather than wrists for the rolling action). The strange thing is that the % contributions used in the video were the same for Men and Women (apart from the legs contribution where the Women were greater than Men) so unsure where they got this data saying that LPGA women 'on average' have higher ribcage rotation than PGA men (unless this is more recent data). Incredibly vague video , especially because he never explained biomechancially how leg participation contributed to clubhead speed. He also seemed to infer active cocking /uncocking wrists (which doesn't make sense to me because it should be a passive CF induced release) Driver Legs: 21% men , 26% women Core: 10% men & women Shoulders: 12% & women Wrist : 56% men & women I think the 'Sandtrap forum' pros also produced a very unscientific video below to demonstrate approx contributions (but specifically to show that vertical GRF play a very small part in generating clubhead speed). But in essence they also agreed with the percentages quoted in Chuck Evans video. Quote From Iacas "Most people talk only about the vertical GRF. But those are a small portion of the GRF, and within the swing itself, an even smaller portion of the contribution to swing speed. Just swinging your arms is about 75% of your swing speed. The horizontal ("rotational") speed (seen in shear GRF forces) are about 20%. The vertical GRF stuff is about 5%. And most people already use a bit of that - almost nobody uses 0% of that 5%." DG I think that Chuck Evans' figures for which body part contributes to clubhead speed, and that are expressed as a percentage, is totally unscientific and nonsensical. How do the legs contribute 2x as much to clubhead speed versus the core (active pelvis rotation and active abdominal oblique contraction that rotate the upper torso)? What are the legs actually doing to produce 2x more swing power than the swing power produced by the combined rotation of the pelvis + upper torso? How do the wrists produce 5X more swing power than the pivot action's induced release of PA#4? I think that it's an insanely unscientific claim!!!! The other video is equally nonsensical! How can one claim that the motion of the arms alone contribute 77% of a golfer's clubhead speed? That value may pertain to that golfer who has a slow pivot, but why should I believe that it pertains to a golfer who has a very efficient pivot action - like Jamie Sadlowski and Cameron Champ? Iacas claims that shear GRF forces produce 20% of a golfer's swing power. How does it produce any swing power? Please explain how twisting the feet against the ground produces any swing power. Jeff.
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Post by dubiousgolfer on Nov 1, 2018 10:06:55 GMT -5
I think they are mistakenly defining % work done by the segments of the body (like that bar chart produced by Nesbitt/Serrano) and then making a vast assumption that it is directly/indirectly associated with the creation of clubhead speed. Imho it is very difficult (maybe currently impossible) to measure what % amounts of energy gets transferred between segments of the body (especially distal segments) and finally through to a share of the kinetic energy of the clubhead.
DG
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Post by imperfectgolfer on Nov 1, 2018 12:46:10 GMT -5
I think they are mistakenly defining % work done by the segments of the body (like that bar chart produced by Nesbitt/Serrano) and then making a vast assumption that it is directly/indirectly associated with the creation of clubhead speed. Imho it is very difficult (maybe currently impossible) to measure what % amounts of energy gets transferred between segments of the body (especially distal segments) and finally through to a share of the kinetic energy of the clubhead. DG What does this part-of-your-sentence statement - "what % amounts of energy gets transferred between segments of the body" - mean? I find the concept of energy transfer between body segments incomprehensible when it comes to thinking about golf swing biomechanics!
Jeff.
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Post by dubiousgolfer on Nov 1, 2018 17:15:07 GMT -5
I think they are mistakenly defining % work done by the segments of the body (like that bar chart produced by Nesbitt/Serrano) and then making a vast assumption that it is directly/indirectly associated with the creation of clubhead speed. Imho it is very difficult (maybe currently impossible) to measure what % amounts of energy gets transferred between segments of the body (especially distal segments) and finally through to a share of the kinetic energy of the clubhead. DG What does this part-of-your-sentence statement - "what % amounts of energy gets transferred between segments of the body" - mean? I find the concept of energy transfer between body segments incomprehensible when it comes to thinking about golf swing biomechanics!
Jeff.
For example , if they monitored a segment of Nesbitt's model in a golf swing, they may have estimated how much work (W) was done in moving that specific segment mass from point A to point B. But how can one estimate what percentage of 'W' was used to move another interconnecting segment , and so on from one segment to another until it reached the hands and clubhead? How could one work out what percentage of the original W actually ended up as energy transferred (via all those interconnecting segments) to the club? To then try and apply the same principle to the workings of a real human body would be very difficult to do and yes, probably incomprehensible. But it might be useful for golfers (even those not interested in the academic side) to at least have a 'high level' understanding of what is powering the golf swing because it could prevent a golfer from trying to ingrain an action based on an incorrect perception. When I go to the golf range it is amazing how many people I see attempting to swing who plainly have very little idea about a CF induced release. DG PS. I think I've misinterpreted Chuck Evans percentages . I thought for example 56% of the total work done by the wrists (ie. motion in space) was transformed somehow into clubhead speed, that 12% of the total work done to move the shoulders was transformed into clubhead speed , etc etc. Those % values are obviously relating to clubhead speed where he infers that 56% of clubhead speed comes from the motion of the wrists uncocking/rolling , 21% from the legs 'doing something', 10% core 'doing something', 12% shoulders 'doing something'. But he never explained what that 'doing something' is and how it gets transformed into clubhead speed. Very confusing indeed considering he spent quite a few minutes identifying 'Power Sources' then ignoring all of them bar one (ie. the wrists).
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Post by dubiousgolfer on Nov 4, 2018 7:59:19 GMT -5
Another 'unscientific' video but shows that there is a complexity about what is actually producing clubhead speed . When he attempts to isolate what he regards as clubhead speed producers they are not additive.
Then we have Mike Malaska with his own opinions on how to increase clubhead speed
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Post by dubiousgolfer on Nov 4, 2018 19:27:04 GMT -5
Quite an interesting article I've just read (some sections that 'caught my eye' I've copied and pasted below especially the research by Anderson using quite a large sample of golfers). www.researchgate.net/publication/311952847_The_sequence_of_body_segment_interactions_in_the_golf_swingAnderson (2007) postulated that adding a golf club to the open link system might interfere with the proximal-to-distal sequencing shown for other “evolved” sports, such as throwing, discussed at the start of this chapter. Accordingly, the club – as an extension to the distal-most segment of our body – does not follow the natural tapering of volume, mass, and length found in body segments and likely requires an adaptation of coordination in the golf swing to achieve optimal speeds and control. Analysis of a dataset consisting of nearly 500 low-handicap and scratch golfers showed that the angular velocities of the pelvis, thorax, and arms peaked at about the same time in the swing, while the clubhead velocity peaked later and very close to impact. Anderson (2007) noted that body segments peaked at around the same time and the non-body segment – the club – peaked later, which could be considered evidence counter to the principle of proximal-to-distal sequencing along the segments mentioned. Anderson (2007) found that several kinetic quantities, such as angular momentum and kinetic energy, did not follow a proximal-to-distal sequence. Similar to angular velocity, distal segments showed higher peak total kinetic energy, but the timings of peak energies were approximately the same for the body segments and later for the club. Findings in the literature on the importance of proximal-to-distal sequencing in the golf swing remain equivocal and have not reached a consensus. Simulation studies have shown that proximal-to-distal sequencing is consistent with optimality Many empirical studies have shown that this sequence is not present, even in elite-level golfers. Elite-level golfers looking to fine-tune their performance may not find it worthwhile to rebuild their swings to follow the proximal-to-distal sequence. Similarly, it may not be safe for golfers with physical constraints to try to achieve the sequence swing outlined in this chapter. The X-Factor Stretch in particular needs further research to determine possible links with and mechanisms of lower back injury, which is already a large and growing problem in golf.
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Post by imperfectgolfer on Nov 4, 2018 22:20:43 GMT -5
Quite an interesting article I've just read (some sections that 'caught my eye' I've copied and pasted below especially the research by Anderson using quite a large sample of golfers). www.researchgate.net/publication/311952847_The_sequence_of_body_segment_interactions_in_the_golf_swingAnderson (2007) postulated that adding a golf club to the open link system might interfere with the proximal-to-distal sequencing shown for other “evolved” sports, such as throwing, discussed at the start of this chapter. Accordingly, the club – as an extension to the distal-most segment of our body – does not follow the natural tapering of volume, mass, and length found in body segments and likely requires an adaptation of coordination in the golf swing to achieve optimal speeds and control. Analysis of a dataset consisting of nearly 500 low-handicap and scratch golfers showed that the angular velocities of the pelvis, thorax, and arms peaked at about the same time in the swing, while the clubhead velocity peaked later and very close to impact. Anderson (2007) noted that body segments peaked at around the same time and the non-body segment – the club – peaked later, which could be considered evidence counter to the principle of proximal-to-distal sequencing along the segments mentioned. Anderson (2007) found that several kinetic quantities, such as angular momentum and kinetic energy, did not follow a proximal-to-distal sequence. Similar to angular velocity, distal segments showed higher peak total kinetic energy, but the timings of peak energies were approximately the same for the body segments and later for the club. Findings in the literature on the importance of proximal-to-distal sequencing in the golf swing remain equivocal and have not reached a consensus. Simulation studies have shown that proximal-to-distal sequencing is consistent with optimality Many empirical studies have shown that this sequence is not present, even in elite-level golfers. Elite-level golfers looking to fine-tune their performance may not find it worthwhile to rebuild their swings to follow the proximal-to-distal sequence. Similarly, it may not be safe for golfers with physical constraints to try to achieve the sequence swing outlined in this chapter. The X-Factor Stretch in particular needs further research to determine possible links with and mechanisms of lower back injury, which is already a large and growing problem in golf. I originally subscribed to the Cochrane and Stubbs model of kinematic sequencing where the pelvis reaches its peak rotational velocity before the shoulders (thorax) reaches its peak rotational velocity, but I have noted in recent years that a number of 3-D studies have shown that the pelvis and shoulders reach their peak rotational speed at roughly the same time in the downswing in some professional golfers. So, I am now more accepting of the idea that there does not have to be a "fixed" pattern of kinematic sequencing other than the fact that the pelvis must rotate first. However, the degree of torso-pelvic separation (dynamic X-factor) can vary significantly among skilled pro golfers and the timing of the peak rotational velocity of the pelvis and thorax (shoulder rotation) can also vary. For example, here is Jamie Sadlowski's 3D graph. Note that his pelvis starts to rotate in his late backswing and it is rotating faster than his thorax, thereby generating a certain amount of dynamic X-factor. However, note that the pelvis and thorax reach their peak speed at roughly the same time in the downswing, although the peak speed of the arm rotation happens slightly later. By contrast, Jon Rahm has a more conventional kinematic sequence. Stop the video at the 7:11 minute time point and look at his 3-D graph. Note that his pelvis reaches its peak rotational speed before the thorax reaches its peak rotational speed. Here is Gary Woodland's 3D graph.
Note that his pelvis and thorax reach their peak rotational speed at the same time - and his kinematic sequencing pattern is similar to Jamie Sadlowski's.
So, from my personal perspective, both kinematic sequence patterns are acceptable - and that article by Lamb & Glazier does not shed new light on this topic. By the way, I found that video by Eric Barzewski ridiculously non-informative and the Malaska video nearly as bad. Jeff.
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Post by dubiousgolfer on Nov 5, 2018 6:16:39 GMT -5
Many thanks Dr Mann
Didn't Eric Barzewski show in a very crude way that the movement of the arms (using the shoulder girdle muscles) 'might' be a significant contributor to clubhead speed?
Malaska's video just seemed to suggest less tension increases speed (nothing too original) but what did you think about his opinion about the grip automatically squaring the club? I've seen this similar opinion mentioned before in a Manuel De La Torre video (see the first 5 mins in the video below)
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Post by imperfectgolfer on Nov 5, 2018 10:20:38 GMT -5
Many thanks Dr Mann Didn't Eric Barzewski show in a very crude way that the movement of the arms (using the shoulder girdle muscles) 'might' be a significant contributor to clubhead speed? Malaska's video just seemed to suggest less tension increases speed (nothing too original) but what did you think about his opinion about the grip automatically squaring the club? I've seen this similar opinion mentioned before in a Manuel De La Torre video (see the first 5 mins in the video below) Of course, the arms contribute to clubhead speed and I don't need Eric's crude demonstration to understand that fact. In a pivot-driven TGM swinging action, there will be no speed if PA#4 (which is basically a left arm motion) is not released by the pivot. Both the arms and the wrists must be relaxed in order for PA#4 and PA#2 to release efficiently. Any tension at the level of the left shoulder socket or left wrist will decrease the efficiency of release of PA#4 => PA#2. In the Leslie King methodology, PA#4 is released via the shoulder girdle muscles. But there will no speed if the left arm is not in a state of efficiently-released, and relaxed, motion. How can the grip automatically cause the clubface to square-up by impact? Manuel DeTorre wrongly claims that the palms must face each other. However, that doesn't happen if a golfer adopts a strong left hand grip and a neutral right hand grip. Here are three examples. Jamie Sadlowski Isn't his left palm facing the inclined plane at impact while his right palm faces the target. They are >60 degrees angled relative to each other. Hunter Mahan Isn't his left palm facing the inclined plane at impact while his right palm faces the target. They are >60 degrees angled relative to each other.
Keegan Bradley
Image 1 shows that he adopts a moderately strong left hand grip and a neutral right hand grip at address where the two palms are >45 degrees out of face-to-face palmar alignment. At impact (image 2), his left palm is facing the inclined plane while his right palm faces the target. Jeff.
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Post by dubiousgolfer on Nov 6, 2018 10:39:49 GMT -5
Many thanks Dr Mann - I am still confused about these LPGA higher hip/ribage rotational speeds compared to PGA men . If its not additional initial speed being caused by extra muscular effort by shoulder girdle muscles (added to the pivot driven element) , then could it be something to do with later retention of lead wrist-cock angle before CF induced release?
Is it possible that PGA players are on average able to retain their wrist cock angles later in their downswing by their ability to apply more pressure force across the shaft in the early-mid downswing phase?
I remember in this video below (posted in a previous thread) where Sasha MacKenzie showed a 'moment of force' that assists lag in the early downswing (10:29 -11:12) until shaft vertical . So could the PGA players be more able to keep the shaft vertical later in their downswing than PGA women? Could this be the reason why their clubhead speed is superior even with less hip/ribcage rotational speed?
DG
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Post by imperfectgolfer on Nov 6, 2018 17:46:14 GMT -5
Many thanks Dr Mann - I am still confused about these LPGA higher hip/ribage rotational speeds compared to PGA men . If its not additional initial speed being caused by extra muscular effort by shoulder girdle muscles (added to the pivot driven element) , then could it be something to do with later retention of lead wrist-cock angle before CF induced release? Is it possible that PGA players are on average able to retain their wrist cock angles later in their downswing by their ability to apply more pressure force across the shaft in the early-mid downswing phase? I remember in this video below (posted in a previous thread) where Sasha MacKenzie showed a 'moment of force' that assists lag in the early downswing (10:29 -11:12) until shaft vertical . So could the PGA players be more able to keep the shaft vertical later in their downswing than PGA women? Could this be the reason why their clubhead speed is superior even with less hip/ribcage rotational speed? DG I am still waiting for the supply of "evidence" that female LPGA golfers move their left shoulder socket faster between P4 => P5 than male PGA golfers. I am not interested in rib cage rotational measurements. Jeff.
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Post by dubiousgolfer on Nov 8, 2018 18:55:41 GMT -5
Many thanks Dr Mann - I am still confused about these LPGA higher hip/ribage rotational speeds compared to PGA men . If its not additional initial speed being caused by extra muscular effort by shoulder girdle muscles (added to the pivot driven element) , then could it be something to do with later retention of lead wrist-cock angle before CF induced release? Is it possible that PGA players are on average able to retain their wrist cock angles later in their downswing by their ability to apply more pressure force across the shaft in the early-mid downswing phase? I remember in this video below (posted in a previous thread) where Sasha MacKenzie showed a 'moment of force' that assists lag in the early downswing (10:29 -11:12) until shaft vertical . So could the PGA players be more able to keep the shaft vertical later in their downswing than PGA women? Could this be the reason why their clubhead speed is superior even with less hip/ribcage rotational speed? DG I am still waiting for the supply of "evidence" that female LPGA golfers move their left shoulder socket faster between P4 => P5 than male PGA golfers. I am not interested in rib cage rotational measurements. Jeff. So can one assume that the left clavicle joints (at both ends) connected to the sternum and left shoulder socket have on average 'a greater degree of joint flexibility' in females than males? That LPGA females can rotate their 'sternum/ribcage/sternoclavicular (SC) joint' quicker (than PGA males) before the 'acromioclavicular joint (AC joint)' starts pulling on the shoulder socket? DG
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Post by imperfectgolfer on Nov 8, 2018 23:07:02 GMT -5
I am still waiting for the supply of "evidence" that female LPGA golfers move their left shoulder socket faster between P4 => P5 than male PGA golfers. I am not interested in rib cage rotational measurements. Jeff. So can one assume that the left clavicle joints (at both ends) connected to the sternum and left shoulder socket have on average 'a greater degree of joint flexibility' in females than males? That LPGA females can rotate their 'sternum/ribcage/sternoclavicular (SC) joint' quicker (than PGA males) before the 'acromioclavicular joint (AC joint)' starts pulling on the shoulder socket? DG I don't know whether females have a different degree of mobility of the scapula relative to the upper torso or different clavicular joint mobility values. I personally don't think that it is relevant. I still want to know whether females can really rotate their left shoulder socket faster than males between P4 and P5 - because that ability should theoretically correlate with the speed of release of PA#4 and it should therefore theoretically increase clubhead speed. I find it difficult to imagine that females actually release PA#4 faster than males - and I would be interested in seeing 3-D values for the speed of release of PA#4 (speed of left arm motion). I can imagine that males may have greater shoulder girdle muscle strength than females and that they can therefore pull their left and right arms downwards faster between P4 and P5.5 and that may increase their ability to hold a greater degree of lag for longer and that specific factor may be responsible for some increased clubhead speed capacity. I still cannot quite understand why males can generate greater clubhead speed than females in the absence of "hard data" about the speed of left shoulder socket motion between P4 and P5 and the speed of left arm motion between P4 and P5.5 , and I therefore remain open-minded about this issue.
I wish I had personal contacts with the owners of MySwingGolf or GEARS, so that they could provide us with the necessary "hard data".
Jeff.
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Post by dubiousgolfer on Nov 9, 2018 22:57:41 GMT -5
Dr Mann
I did ask Jon Sinclair about whether the data would be made public and also to confirm rotational stats of LPGA vs PGA . He sent me a reply as per below.
"My data certainly shows the ladies rotations on average higher. Not just thorax but pelvis, arms and club.
The easiest way I can put it is that it is easier to spin a smaller object than a bigger one. However that doesn’t mean that the outside edges of that smaller object will be moving faster than the larger one."
I think the analogy he is trying to describe is similar to the spinning ice-skater whose arms/hands are initially pulled in but then suddenly stretched out. On first observation we think the whole rotation has slowed down (ie. we look at the body) , but in fact the hands are moving faster than when they are pulled in.
Not sure how the above information can be used to explain why PGA golfers can still generate greater clubhead speed than LPGA but with slower angular velocities of thorax, pelvis, arms and club.
My very tenuous possible explanation is below:
If I just looked at the velocity of the clubs COG in the downswing , it should be:
velocity = radius x angular acceleration
If LPGA have greater angular acceleration, the PGA men must be swinging the club's COG on a larger radius that more than compensates for their inferior angular acceleration.
That larger radius can be achieved in the early downswing when the club's COG is on a straighter path (an arc path with a large radius). Which suggest that the PGA men are retaining lag better than the LPGA women until CF induced release (even with slower angular velocities of thorax, pelvis, arms, club). The CF induced release will increase the angular velocity into impact with a greater clubhead speed than LPGA players.
The problem here is whether that increased 'angular velocity' due to CF induced release must still be less than LPGA women? If yes, then the formula 'VELOCITY = RADIUS X ANGULAR ACCELERATION' must still apply at least into impact. So the radius of the club's COG into impact for PGA men must again more than compensate for their inferior angular acceleration (this doesn't seem a very likely scenario to me)
I can only assume that they have taken an average of the 'pelvis /thorax/arms/club' rotation over the whole of the downswing. That PGA men will likely have superior clubhead COG angular velocity and CHS after CF induced release into impact.
DG
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Post by imperfectgolfer on Nov 10, 2018 1:16:59 GMT -5
Dr Mann I did ask Jon Sinclair about whether the data would be made public and also to confirm rotational stats of LPGA vs PGA . He sent me a reply as per below. "My data certainly shows the ladies rotations on average higher. Not just thorax but pelvis, arms and club. The easiest way I can put it is that it is easier to spin a smaller object than a bigger one. However that doesn’t mean that the outside edges of that smaller object will be moving faster than the larger one." I think the analogy he is trying to describe is similar to the spinning ice-skater whose arms/hands are initially pulled in but then suddenly stretched out. On first observation we think the whole rotation has slowed down (ie. we look at the body) , but in fact the hands are moving faster than when they are pulled in. Not sure how the above information can be used to explain why PGA golfers can still generate greater clubhead speed than LPGA but with slower angular velocities of thorax, pelvis, arms and club. My very tenuous possible explanation is below: If I just looked at the velocity of the clubs COG in the downswing , it should be: velocity = radius x angular acceleration If LPGA have greater angular acceleration, the PGA men must be swinging the club's COG on a larger radius that more than compensates for their inferior angular acceleration. That larger radius can be achieved in the early downswing when the club's COG is on a straighter path (an arc path with a large radius). Which suggest that the PGA men are retaining lag better than the LPGA women until CF induced release (even with slower angular velocities of thorax, pelvis, arms, club). The CF induced release will increase the angular velocity into impact with a greater clubhead speed than LPGA players. The problem here is whether that increased 'angular velocity' due to CF induced release must still be less than LPGA women? If yes, then the formula 'VELOCITY = RADIUS X ANGULAR ACCELERATION' must still apply at least into impact. So the radius of the club's COG into impact for PGA men must again more than compensate for their inferior angular acceleration (this doesn't seem a very likely scenario to me) I can only assume that they have taken an average of the 'pelvis /thorax/arms/club' rotation over the whole of the downswing. That PGA men will likely have superior clubhead COG angular velocity and CHS after CF induced release into impact. DG I am confused! Sinclair apparently claims that not only are LPGA female golfers generating a faster angular rotation of the pelvis and thorax, but he also claims that it also applies to the arms and clubshaft. If it applies to the clubshaft, then the primary rational explanation for the increased clubhead speed of male PGA golfers is presumably an increased swing radius (length of the left arm + clubshaft). Now, that assertion of increased swing radius may apply to some tall male golfers who are >6 feet tall, but many PGA tour golfers are relatively short eg. Jason Day. Also, Jamie Sadlowski is only 5'10" and he hits the ball >400 yards. I really would like to see Sinclair's data and I would also like to see him explain in detail why male PGA tour golfers drive the ball further than female LPGA golfers. Jeff.
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