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Post by imperfectgolfer on Dec 24, 2011 10:29:09 GMT -5
in the MJ/BM RACP release action swing philosophy, they state that the low point of the hand arc path must be opposite the right thigh. See this 3jack thread. richie3jack.proboards.com/index.cgi?board=general&action=display&thread=2748&page=4Note Mike McNary's hand arc path. It doesn't fit the MJ/BM pattern and his hand arc path low point is near impact - which is not surprising considering the fact that Mike moves his head/spine forwards during his downswing action and his left knee is more bent at impact than it was at address. That only demonstrates that the "fixed" idea that the low point of the hand arc path must be nearer the right thigh is totally arbitrary and not based on a solid understanding of golf swing biomechanics. Thankfully, Mike doesn't employ a "run-up and jumping-up" action in his swing - like Tiger Woods, who sometimes bobs-up-and-down" far too much. Jeff.
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Post by walther on Dec 24, 2011 11:25:18 GMT -5
Mike hits a 7 iron almost 200 yards. Not sure that he "leaves much on the table."
W
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Post by natep on Dec 24, 2011 11:32:54 GMT -5
I would be astonished if that was true. I'd have to see that to believe it. Thats about 30 yards longer than Tiger hits a 7-iron. Really? Dana Dahlquist made a post, maybe in that same 3jack thread, that the CP pattern that McNary uses/teaches puts up terrible Trackman numbers, with too steep of an angle of attack and he loses distance because of it. Based on his knowledge of the pattern, and the shape of his hand path I'm inclined to believe he's correct.
Here's a 7-iron swing:
Also, Jeff, why would you say that the hand path that BM recommends is BS and just arbitrary? It's based on Miura's paramatric acceleration and Nesbit's optimized hand path study.
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Post by imperfectgolfer on Dec 24, 2011 12:18:06 GMT -5
Natep, You wrote-: "Also, Jeff, why would you say that the hand path that BM recommends is BS and just arbitrary? It's based on Miura's paramatric acceleration and Nesbit's optimized hand path study." I regard Nesbit's model as arbitrary. If you want to get an additional 5% clubhead speed via the biomechanical mechanism of parametric acceleration, then go ahead and use a hand path pattern where the low point of the clubhead arc is well behind impact. However, if a golfer likes Mike McNary's swing action, it represents an alternative hand arc path pattern. Lee Trevino also used a hand arc path where the low point of his hand arc was closer to impact than his right thigh - and he was a great ball-striker. I think that it is optional whether one should have a straight left leg at impact (Like Tiger) or a bent left knee (Like Hogan, Trevino, McNary and Moe Norman). Moe Norman Jeff.
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Post by imperfectgolfer on Dec 24, 2011 12:26:23 GMT -5
nmg, You wrote-: "PS there is some question of "optimal" means. Here's my definition: maximum effect for minimum work." That's a mechanical definition. I think of "optimal" only in terms of human biomechanics, which can vary from golf swing style-to-golf swing style. You also wrote-: "I think it silly to criticize tiger's swing(s)." I don't - I think that Tiger had a great swing in 2000 (and when he performed that slow-mo Nike Commercial) but I think that this is a terrible swing action. Here are capture images Image 3 shows his impact position. I drew a red line through his shaft and that red line passes through his right elbow - which shows that he is on the elbow plane at impact. Image 2 shows him at the delivery position. Note that his clubshaft (straight blue line) is parallel to the ball-target line (straight yellow line) which means that he is not underplane (defining underplane as being a clubshaft that is coming too much from in-to-out). However, note that his hands are lower-to-the-ground in image 1 and 2 - relative to his hands at impact. That is due to the fact that he has a lot of knee flex and hip bend flex in his early-mid downswing. Image 1 shows his exaggerated "sit-down" look where he has a lot of knee flex and hip flex. In the late downswing, he abruptly straightens his left leg and "jumps up" and that action lifts his hands to the elbow plane by impact. Note that he is "standing-up" at impact due to the lesser amount of knee/hip flex at impact, and that his head is much higher in image 3 (relative to image 1). Image 4 shows his clubshaft/clubhead in the late downswing - note that the clubhead is outside the ball-target line (straight yellow line). In image 5, I have traced the clubhead arc (curved yellow line) in the pre-impact time period which shows that his clubhead moves out-to-in just before impact (curved red arrowed line represents its curved directional motion) and it produces a straight pull shot because the clubhead path/clubface orientation at impact is directed leftward. I think that it is causally due to his "jumping up" action which pulls his hands abruptly upwards just before impact, and that motion affects the 3-D clubhead arc's path in space. The clubhead arc was moving more groundwards during his early-mid downswing due to his exaggerated knee/hip flex action, and that caused the clubhead to temporarily move outside the ball-target line in the first half of his late downswing. Then, the clubhead is pulled more upwards as he "jumps-up" at impact (compare the height of his pelvis in image 3 to the height of his pelvis in image 1) and as he pulls his hands to a level that is further from the ground. I don't mind the idea of parametric acceleration with a low point of the hand arc path being well behind low point. In fact, my favorite golfer - Annika Sorenstam - manifests that pattern, but she doesn't bob-up-and-down. Jeff.
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Post by natep on Dec 24, 2011 16:23:26 GMT -5
Natep, You wrote-: "Also, Jeff, why would you say that the hand path that BM recommends is BS and just arbitrary? It's based on Miura's paramatric acceleration and Nesbit's optimized hand path study." I regard Nesbit's model as arbitrary. If you want to get an additional 5% clubhead speed via the biomechanical mechanism of parametric acceleration, then go ahead and use a hand path pattern where the low point of the clubhead arc is well behind impact. However, if a golfer likes Mike McNary's swing action, it represents an alternative hand arc path pattern. Lee Trevino also used a hand arc path where the low point of his hand arc was closer to impact than his right thigh - and he was a great ball-striker. I think that it is optional whether one should have a straight left leg at impact (Like Tiger) or a bent left knee (Like Hogan, Trevino, McNary and Moe Norman). Moe Norman Jeff. It's not just the parametric acceleration speed gains, but also the optimal angle of attack that results from Nesbit's optimized hand path. Of course there are other options, you can play cross-handed on one leg if you want to. That doesnt mean Nesbit's hand path isnt optimal, though. Not all hand paths are created equal. Trevino's exclusively low ball flight is well-documented.
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Post by imperfectgolfer on Dec 24, 2011 16:57:34 GMT -5
I didn't state that Nesbit's hand path is not OK - I simply have seen no "evidence" that it is better than other hand paths. His hand arc path pattern is a computer construct model. Also, I will take your assertion of a direct relationship between a hand arc path's low point and optimum clubhead attack angles more seriously if you present "evidence" to support you assertion - instead of parroting someone like Dana, who has also not presented any "evidence". I would also like to see the effect of ball position taken into account in that "evidence".
Jeff.
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Post by tomdavis76 on Dec 24, 2011 17:32:52 GMT -5
in the MJ/BM RACP release action swing philosophy, they state that the low point of the hand arc path must be opposite the right thigh. Jeff- Did they really say "must"? I think that is a strawman created by you. All they did was recommend the in and up hand path consistent with Miura's parametric acceleration and supported by 2D modeling. Some have a lot of up and in, like Sadlowski, some have none, like McNary, Trevino and Brian Gay. I know who hits it longer, not necessarily straighter. Maybe I missed it, but I don't recall claims that there was something miraculous about it, just that it appeared to add some clubhead speed. Tom
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Post by gmbtempe on Dec 24, 2011 17:51:19 GMT -5
Mike hits a 7 iron almost 200 yards. Not sure that he "leaves much on the table." W I have been told the opposite, that he hits it rather short, but super solid. I have not seen in myself but I trust this source as he hit with him many many times.
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Post by imperfectgolfer on Dec 24, 2011 18:23:42 GMT -5
Tom,
You wrote-: "Did they really say "must"? I think that is a strawman created by you. All they did was recommend the in and up hand path consistent with Miura's parametric acceleration and supported by 2D modeling."
I think that MJ/BM state "must" - based on viewing many of their videos on this topic- and I do not think that they regard it as optional.
Jeff.
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Post by richie3jack on Dec 24, 2011 18:40:23 GMT -5
I would be astonished if that was true. I'd have to see that to believe it. Thats about 30 yards longer than Tiger hits a 7-iron. Really? Dana Dahlquist made a post, maybe in that same 3jack thread, that the CP pattern that McNary uses/teaches puts up terrible Trackman numbers, with too steep of an angle of attack and he loses distance because of it. Based on his knowledge of the pattern, and the shape of his hand path I'm inclined to believe he's correct. Dana really didn't say that. He never even mentioned McNary. And he never said that CP would put up 'terrible Trackman numbers.' Dana said that the problem with CP is that it 'crashes down on the ball too much' and that doesn't jive with the new ball. I don't really agree with that notion given Boo Weekley hits down by -3.5* according to Trackman and I had ranked #1 in Advanced Total Driving. I know that Mac still hits it quite long, particularly for a golfer his age and he doesn't look like he's trying to kill it. Neither does Couples, who hits bombs. The other thing is that the pic in the original post was of a certain model trying to hit a certain window by McNary. I've got old video of McNary with the coupling point rising into impact. Same with Mac. Depends on what they are trying to do with the ball. 3JACK
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Post by natep on Dec 24, 2011 18:49:12 GMT -5
Dana was talking specifically about McNary and says he hit down too much on the ball and has too steep of AoA and doesnt hit it as far as he could. I dont think I misrepresented his comments at all. He didnt specifically say "terrible TM numbers" but he mentions that the baseline needs to be shifted to get acceptable TM numbers, so I'm assuming if they need to be changed they're at the very least undesireable. Here's the exact quote: Dana wrote: "The over all positions Mikes demoing doing CP are great. He at times hits it far enough. The only issue with the CP model is angle of attack on Trackman. It’s way too crashy for today’s golf ball. Mac has not experimented on this yet, however he has been told this. Take a lower spinning ball and make the angle of attack to sharp, you got problems. I think his stuff may change some in the next year because of this. Yes the dynamics are fantastic, however there are some pieces that develop errors if your doing a CP model swing. Hence the reason guys CF longer clubs and make baseline shifts, otherwise the ball goes shorter. Same issue another well know darome guy has been having on tour “ won’t name him” his attack angle is a touch higher than needed. We have been going over what is the best mix for stability with the models. Should be good for him in the long run. Read more: richie3jack.proboards.com/index.cgi?board=general&action=display&thread=2748&page=3#ixzz1hV00RgiV"
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Post by richie3jack on Dec 24, 2011 19:18:22 GMT -5
Dana was talking specifically about McNary and says he hit down too much on the ball and has too steep of AoA and doesnt hit it as far as he could. I dont think I misrepresented his comments at all. He didnt specifically say "terrible TM numbers Uhhhh...that's misrepresenting what he said. 3JACK
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Post by natep on Dec 24, 2011 19:21:05 GMT -5
I was paraphrasing, hopefully my last post clears it up.
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Post by tomdavis76 on Dec 24, 2011 19:55:58 GMT -5
Tom, You wrote-: "Did they really say "must"? I think that is a strawman created by you. All they did was recommend the in and up hand path consistent with Miura's parametric acceleration and supported by 2D modeling." I think that MJ/BM state "must" - based on viewing many of their videos on this topic- and I do not think that they regard it as optional. Jeff. OK, identify a video and the time into it where they say "must". Obviously it can't be "must" because some very good golfers don't do it! Aren't they recommending a pattern they like? What do they say will happen if you DON'T do it? You'll miss the ball? Come on. And what is so bad about recommending it? How do you think it will HURT?
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