Is it not a big deal Dustin Johnson hit 3w/6i on the 18th green at PB?

[JESII]

Jim - had to go look that up, just to keep this going. Let's stick to just club head speed (and leave alone the possibility that a longer shaft might produce more mishits). But we do have to note, apparently, that a longer shaft might also weigh more than a shorter one (which might 'even things out', club head speed wise). So, interestingly, the example engineers with Cleveland Golf give is this: "The same energy that would produce a swing of about 96 miles per hour with a 45-inch driver weighing 325 grams would generate a swing speed of roughly 102 mph with a 46½-inch driver weighing 285 grams."

Mark - i do remember that. But Nick Price's comments made me think that not all of them were following that, or at least that all 90%s are not created equal.

Peter

Agree that there are trade-offs for the longer clubs, but we've heard on this thread that each mph increase in club head speed equals about 3 yards...

[Peter Pallotta]

Tee hee....love those...., in this case meant to leave me to do the math....which totals about 18 extra yards....just with the new shafts alone...

(btw, good previous post, the psychology strikes me as sound, but what do I know....)

[DMoriarty]

Interesting tweet from a friend of mine
Gary Woodland hitting on range recently
2014 Callaway BB driver 316 carry, 127 CH speed, 187 ball speed
1980's wood driver   268 carry, 114 CH speed, 168 ball speed
similar spin rate on both
ProV1 x ball, so you can probably subtract a few yards if using balata, putting him near 260 carry?
More Nicklaus types of numbers-who was a hell of an athlete as well

Jeff,  Thanks for posting those numbers.  Very interesting.  

I've seen talk of "smash factor" (ball speed/club head speed) and as I understand it it is a good way of measuring/comparing the efficiency of transfer of energy from the club head to the ball. I've read that approaching 1.5 is a very efficient transfer of energy.   Mr. Woodland was at 1.472 with the new driver and 1.474 with the old driver.  Almost identical.  As for efficient transfer of energy, he doesn't seem to have lost anything at all with the older driver.  In fact he was a hair better with the old club.

That said, the carry distance with the old club wasn't nearly as proportional as the energy transfer, and seems surprisingly short with a 168 mph ball speed, doesn't it?   Did he happen to mention the ball flight/launch angle and spin?  I tried to duplicate Woodland's results on Bryan's Flightscope Optimizer website, and the only way I can get that short of a carry is with a really low launch and spin (9, 2100) or a really high spin (4800).
________________________________

My contention is that Woodland was using what is, for him, the perfect driver and ball combo in today's gear but if he took the time he'd find a driver/ball/swing combo to close some of that gap. Not all, but a healthy amount.

Jim, I agree he could "optimize" and make some of the distance, but back then his "optimization" options were severely limited as compared to today.  Balata was considered pretty much the only ball choice for top players.  The heads were smaller, the shafts heavier, and a longer shaft would have been heavier still.

As Peter suggests, there may have been very good equipment/technology related reasons why they weren't using 46 inch shafts or swinging at 127 mph back then. For example, a longer shaft not only means more weight, it also may impact launch conditions, make quality of the strike less efficient, and/or make sidespin more prevalent.  Golfers have been experimenting with longer shafts for at least a 100 years (I have seen a photo of Travis trying to swing something like a 50 inch shaft) but given that longer shafts never caught on even among elite players, they must have had reason.  I think that, for better players, shaft lengths reflect what seems most efficient for the technology of the time.  It doesn't make sense to think they could have slapped 46 inch steel shafts on clubs of the mid-1980's and not have lost anything.  Otherwise they would have.

Added:  By the way, Jim, in thinking about the old patent applications where tests were performed outside on grass, it probably makes more sense to focus on carry distances, as roll is so variable with the conditions.

[DMoriarty]

Here is a link to an interesting recent (Aug. 2011) patent application from Nike, for a ball which they claim "has a typical initial velocity at a low club head speed, but an increased initial velocity at a high club head speed."  

www.google.com/patents/US20130210544

Given their comparison set (Pro V1, Nike One, Nike One D, Callaway Tour i(s)) and the description, this is supposed to be a high performance ball aimed at the high swing speed player. (Notably they didn't include the Pro V1x, perhaps because they didn't want to look bad.)  

So what does "typical initial velocity at low club head speed" mean to Nike?  Here are their initial velocity numbers for an 80 mph swing with a swing robot and a Nike SQ Dymo 10.5° driver.  (complete specifications in the application.)


Ball         ballspd   spin   Lnch   crry   total dist.
Prototype      88   2181   10.8   85   125
OneTourD      90   2139   10.9   88   128
Pro V1          88   2243   10.8   86   125
Tour(i)s         88   2377   10.6   84   123
One Tour      89   2418   10.6   88   126

For all these balls, a swing speed of 80 mph produced an initial ball speed of 88 to 90 mph, and total carry distances in the mid-80s. With a generous 40 yards of roll, the longest of the bunch is only 128 yards total. Granted, the launch angle and spin are way too low for this slow a swing, and maybe a different driver could "optimize" these and improve distance and carry a bit. But what about the ball speed? There isn't much optimization one can do with a ball speed of 88-90 mph.

This is what Nike scientists consider to be "typical initial velocity at low club head speed?"    If 88-90 ball speed is really "typical" with an 80 mph swing speed, then there is no way that the technology behind these balls has improved the distance performance of slow club head swing players.  

[JESII]

Regarding the Woodland experiment; everything I've heard about today's players hitting old persimmons with new balls is that ball flies incredibly low so I'm sure that's it David, something along the lines of your 9* launch and 2100 spin rate.

Regardless, did you notice that he lost 13 mph in swing speed? Certainly from a combination of shorter and heavier shaft. Can't imagine in this test he was artificially gearing back for accuracy. According to the estimates in your earlier post, that's over 30 yards right there.

[jeffwarne]

David,
The wood driver was 3050ish and the modern driver was 2980ish so not real different
I suspect the launch was  a bit lower with the wood, but no info

My guess is as Jim says that it was random wood driver with zero optimization or preference, and probably his perfectly optimized and preferred driver.
Perhaps a lower launch kept it from optimizing carry?

anecdotally, my clubhead speed with a wooden driver was 108(of course who knows how a swingtech computer  compares to trackman) when I was 30 and would certainly struggle then to carry a ball 250 yards(240 was more like it), which using 3yards x 6mph (114-108) would seem to indicate he got easily more than 18 yards of carry than I would then, though I would've been using a balata ball

[Peter Pallotta]

Jeff - all this is perfect for your radio show, with Nick Price and Gary Woodland all talking technology, from their experience.Boring you say? Oh no, a geek's dream (and, let's face it, if your a golfer you're a geek!)

Peter

[Bryan Izatt]

Haven't followed this thread but re the Bryan's graphics: is the relationship of Y to X actually linear? Qualitatively I have read many times it's not, that Tour players (maybe even just the fastest swinging among that cohort) achieve a distance gain disproportionate to their swing speed differential to real golfers like you and me.

Yes / no / maybe?

No.

The disproportionate gain thing is a myth.  The myth was dispelled in a study by Steve Quintavalla of the USGA in 2006. 

A brief summary of the study can be found at http://www.usga.org/news/2006/April/Speed-Vs--Distance--Do-Long-Hitters-Get-An-Unfair-Benefit-/.  There is a link in it to the complete study.

The relationship is linear for the most part with a small tail off at the top end penalizing really fast swingers.


David has a theory that there is a greater distance gain per mph increase in swing speed with the ProV1x than there was for the Tour Balata ball.  In essence he thinks that the red Tour Balata line in my simple graph was flatter and crossed over the blue ProV1x line at some swing speed.  None of us have found credible evidence that that was true.  My unscientific test was a rudimentary attempt to test the theory.  It appears the lines may cross below 80 mph but the data really isn't very credible.  The search will go on.

[Jim Sherma]

Another part of the discussion that is being left is how controllable the different balls were at higher swing speeds. The balatas certainly spun more off of persimmons for minor misses. I know that I rarely swung 100% with the old equipment while the new equipment penalizes slight mishits very marginally.

[Bryan Izatt]

Doug,

Now, I have no doubt I'd have added a few mph to those numbers if instead of a 42.75" 130g shaft I had a modern lighter longer graphite shaft.  Exactly how many, I have no idea.  I don't see where you assume this mysterious 10% jump in swing speeds over the past few decades has come from.  Do you think the longer/lighter shaft has that much effect?  That seems doubtful to me.  Or is this yet another attempt to claim "fitness" has anything do with with swing speed, despite all the evidence that shows the distance jumps happening only in certain distinct points in time where technology changed - PROVING that fitness has little or nothing to do with the distance gains.

The mysterious 10% is not mysterious at all.  I was merely comparing the ODS test swing speed of 109 mph in the 1970's to the current ODS test swing speed of 120 mph.  In both cases they were supposed to have been set to reflect swing speeds of reasonably long hitters.  These two numbers reflect how much faster the USGA thinks players are swinging now vs thirty years ago. Take it for what it's worth.

My apologies if I insulted you by saying that your swing speed was 109 mph.  Your much higher numbers are very, very impressive for that time.

Yes, I think the swing speed increase is due to improvements in the clubs primarily.  Lighter heads, lighter shafts, lighter grips all lead to faster swings even given the same input.  Higher MOI's have also enabled players to take harder swings with less penalized misses.  I think that a 11 mph gain in swing speed is very possible.  The Gary Woodland test above shows a 13 mph gain - in the same ball park.

No, I wasn't attributing it to improved fitness.  I think that that is a tertiary effect, but still a small contributor.  It certainly hasn't seemed to have hurt Tiger or all those that have followed his fitness regime.  Gary Woodland, for instance is 3" or 4" taller than Nicklaus (Minnesota Fats) giving a longer arc.  I would guess that players on tour today, on average, are taller and stronger than they were 30 years ago, but that's a whole other path to go down.

[Patrick_Mucci]

Bryan,

Do you think it's possible to construct a study where you want the study to confirm the outcome that you've already determined ?

[Pat Burke]

I have a MacGregor Super Eye-o-Matic with an X-100 and a leather grip.
Also a Cleveland TC-15 also with an X-100.

I take them out when I get a wild hair.
Both the woods are around 8.5 degrees and a little more than 1 degree open.

It takes a few swings to figure out how to get a ProV1 airborne.
I tend to hit them very solid, low fade, and very accurate.  Can't get a draw much
higher than ass high

Hit the drivers about 20 yards behind my current Callaway (carry)

My experience with old balls.  Mostly Maxfli HT has been that I hit them with my new clubs,
astonishingly close to the ProV1.  Surprises me every time.  Funny, never hit the old balls with the woods

[DMoriarty]

David,
The wood driver was 3050ish and the modern driver was 2980ish so not real different
I suspect the launch was  a bit lower with the wood, but no info

Thanks Jeff.  According to the flightscope optimizer website, if you plug in 168 mph ball speed and 3050 spin, the launch angle has to be around 6 degrees to get a carry of only 268 yards. It seems from various sources (including Jim's pst, and Pat Burke's indication that it takes a few swings to get the ball airborne with the old drivers) that the old clubs launch the new balls much lower.
__________________________________________________

Jim

Regardless, did you notice that he lost 13 mph in swing speed? Certainly from a combination of shorter and heavier shaft. Can't imagine in this test he was artificially gearing back for accuracy. According to the estimates in your earlier post, that's over 30 yards right there.

Yes, I noticed the 13 mph increase.  Given that he was the same guy with both swings, I would attribute this to difference the different equipment, which is another way of saying the increase is attributable to new technology.  A couple of minor clarifications.
-- The USGA showed an average 3 yard change in distance per one mph change from around 90 mph to 110 mph.  From 110 to 120 the change was less than 2.5 yards.  Following their reasoning, the change from 120-130 should be substantially less than this, probably under 2 yards per one mph change in club head speed.
-- I'm not sure what you mean by "artificially gearing back" but I'd expect him (or any golfer) to try and swing with much more control when trying to hit with the old equipment, especially initially.  The club head size is just so strikingly different visually, that it seems to me that a natural reaction would be to hold back to try and make solid contact.  I'd think it would take a while to get used to.  Try it and I think you'll see what i mean.  Over time I'd bet his swing speed with the old equipment would increase somewhat.  

Here is a photo from wikipedia of a modern driver next to an early 80's driver.  

[Doug Siebert]

Doug,

Now, I have no doubt I'd have added a few mph to those numbers if instead of a 42.75" 130g shaft I had a modern lighter longer graphite shaft.  Exactly how many, I have no idea.  I don't see where you assume this mysterious 10% jump in swing speeds over the past few decades has come from.  Do you think the longer/lighter shaft has that much effect?  That seems doubtful to me.  Or is this yet another attempt to claim "fitness" has anything do with with swing speed, despite all the evidence that shows the distance jumps happening only in certain distinct points in time where technology changed - PROVING that fitness has little or nothing to do with the distance gains.

The mysterious 10% is not mysterious at all.  I was merely comparing the ODS test swing speed of 109 mph in the 1970's to the current ODS test swing speed of 120 mph.  In both cases they were supposed to have been set to reflect swing speeds of reasonably long hitters.  These two numbers reflect how much faster the USGA thinks players are swinging now vs thirty years ago. Take it for what it's worth.

My apologies if I insulted you by saying that your swing speed was 109 mph.  Your much higher numbers are very, very impressive for that time.

Yes, I think the swing speed increase is due to improvements in the clubs primarily.  Lighter heads, lighter shafts, lighter grips all lead to faster swings even given the same input.  Higher MOI's have also enabled players to take harder swings with less penalized misses.  I think that a 11 mph gain in swing speed is very possible.  The Gary Woodland test above shows a 13 mph gain - in the same ball park.

No, I wasn't attributing it to improved fitness.  I think that that is a tertiary effect, but still a small contributor.  It certainly hasn't seemed to have hurt Tiger or all those that have followed his fitness regime.  Gary Woodland, for instance is 3" or 4" taller than Nicklaus (Minnesota Fats) giving a longer arc.  I would guess that players on tour today, on average, are taller and stronger than they were 30 years ago, but that's a whole other path to go down.

I wasn't insulted, nor was I trying to impress anyone.  My point was that ordinary golfers had high swing speeds back in the 80s, just as they do today.  I didn't have any fitness regimen back then, unless drinking until dawn and playing hung over counts as a regimen.  I just happened to be born with a few extra fast twitch fibers in my wrists and shoulders, I suppose.  It wasn't wasn't due to technique or training, so I can't take any credit for my clubhead speed anymore than someone can take credit for buying a $10,000 winner scratch-off lottery ticket.

While fitness didn't "hurt" Tiger, remember when he came along as a scrawny kid he was outhitting everyone by more than he ever did after he bulked up from his fitness regimen.  Tiger is so good at controlling his trajectory and spin that the new ball/driver reduced his advantage over less talented pros, because the old equipment required more skill to achieve the best distance.  If being more fit helped him at all, it is certainly well hidden in the stats that show him with less an advantage over the average tour player as well as against the top 10 longer hitters.

I'm uncertain about the Woodland results - I'd rather see someone who isn't the longest hitter on tour, as well as one of the older guys who grew up playing that equipment.  Does anyone have any stats for average swing speed on tour today, versus back in the 80s?  If it is really anything close to a 13 mph difference I'd be shocked.

[Doug Siebert]

Here is a link to an interesting recent (Aug. 2011) patent application from Nike, for a ball which they claim "has a typical initial velocity at a low club head speed, but an increased initial velocity at a high club head speed."  

www.google.com/patents/US20130210544

Given their comparison set (Pro V1, Nike One, Nike One D, Callaway Tour i(s)) and the description, this is supposed to be a high performance ball aimed at the high swing speed player. (Notably they didn't include the Pro V1x, perhaps because they didn't want to look bad.)  

So what does "typical initial velocity at low club head speed" mean to Nike?  Here are their initial velocity numbers for an 80 mph swing with a swing robot and a Nike SQ Dymo 10.5° driver.  (complete specifications in the application.)


Ball         ballspd   spin   Lnch   crry   total dist.
Prototype      88   2181   10.8   85   125
OneTourD      90   2139   10.9   88   128
Pro V1          88   2243   10.8   86   125
Tour(i)s         88   2377   10.6   84   123
One Tour      89   2418   10.6   88   126

For all these balls, a swing speed of 80 mph produced an initial ball speed of 88 to 90 mph, and total carry distances in the mid-80s. With a generous 40 yards of roll, the longest of the bunch is only 128 yards total. Granted, the launch angle and spin are way too low for this slow a swing, and maybe a different driver could "optimize" these and improve distance and carry a bit. But what about the ball speed? There isn't much optimization one can do with a ball speed of 88-90 mph.

This is what Nike scientists consider to be "typical initial velocity at low club head speed?"    If 88-90 ball speed is really "typical" with an 80 mph swing speed, then there is no way that the technology behind these balls has improved the distance performance of slow club head swing players.  

If this is correct, then there really IS a supralinear increase in distance at higher swing speeds.  Look at the huge difference between 80 mph to 95 mph versus 80 mph to 110 mph.  3x the additional distance from 2x the additional clubhead speed!

I thought this Quintavella study had debunked that?  Either that study is wrong, or these numbers are wrong.  Does an 80 mph clubhead speed really produce such pitiful distance?

[JESII]

Doug,

Must be something screwy about this test...at least compared to the Trackman ideal measurements Bryan posted on reply #159.

[Padraig Dooley]

Here's some testing I did

http://0to300golf.blogspot.ie/2012/12/titanium-versus-persimmon.html

http://0to300golf.blogspot.ie/2013/03/titleist-tour-balata-90-v-titleist-pro.html

http://0to300golf.blogspot.ie/2013/03/persimmon-balata-v-titanium-pro-v1x.html

Didn't get the same differences as Gary Woodland. The ball made the biggest difference for me.

[DMoriarty]

Thanks, Padraig.  Very interesting.
________________________________________


Bryan,  Regarding your post 457, I think I'll stick with my own statement of my theory in post 440.

That said, your graph does provide very rough idea of what I am talking about here. According to your rough observations:
-- At around an 80 mph swing speed there doesn't appear to be a distance difference between the Pro V1x and the Balata.  
-- At around 103 mph there appears to be about a 7 yards difference.
-- At around 110 mph the difference appears to be about 10 yards difference.

This suggests that the faster swingers, and not slower swingers, have benefited more from the new technology, does it not?

As you know, at least one other source suggests the gap between balata and ProV1x much larger at around 110 mph swing speed.  In the experiment conducted by Andrew Ric, his 110 mph swinger hit the the ProV1x about 46 yards longer than the Balata.  

www.andrewricegolf.com/tag/tour-balata/‎

Rice didn't test at 80 mph, but it is hard to imagine that a 80 mph golfer would the Pro V1x 46 yards further, isn't it?

None of us have found credible evidence that that was true.

I don't think this is quite accurate. There is ample evidence that fast swingers have benefited, and there is evidence out there that average golfers have not benefited much distance-wise from the new technology.  The R&A study, for example, which indicates that average driver distance has only increased 3 yards.  And your own observations above.

On the other hand, none of us have found even a hint of evidence that golfers with slow swings have benefited as much from the new technology as golfers with high swing speeds.  Have we?
______________________________________________________________

Doug,

Must be something screwy about this test...at least compared to the Trackman ideal measurements Bryan posted on reply #159.

Jim, Those numbers are pretty shocking, but I am not sure that we can just throw them out based on that "ideal" trackman chart.

[Bryan Izatt]

Does anyone know the math on how much speed the club head picks up based on 2 inch longer shafts? Assuming everything else (core rotational speed) is exactly the same.

This site has some charts answering your question.  It also addresses the impact of shaft weight and clubhead mass amongst other things.  It's in metric terms.

Two inches longer in the shaft will get you about 5.5 yards according to this study. 

Going from a 120 gm shaft to a 65 gm shaft would get you 7.7 yards.

http://www.tutelman.com/golf/swing/golfSwingPhysics4.php

[Garland Bayley]

Bryan,

That is a great find. My reading says clubhead/ball materials (the collision factors) have caused about a 20 meter increase, and light weight shafts have caused about a 10 meter increase.

[Bryan Izatt]

Interesting tweet from a friend of mine
Gary Woodland hitting on range recently
2014 Callaway BB driver 316 carry, 127 CH speed, 187 ball speed
1980's wood driver   268 carry, 114 CH speed, 168 ball speed
similar spin rate on both
ProV1 x ball, so you can probably subtract a few yards if using balata, putting him near 260 carry?
More Nicklaus types of numbers-who was a hell of an athlete as well

Jeff,  Thanks for posting those numbers.  Very interesting.  

I've seen talk of "smash factor" (ball speed/club head speed) and as I understand it it is a good way of measuring/comparing the efficiency of transfer of energy from the club head to the ball. I've read that approaching 1.5 is a very efficient transfer of energy.   Mr. Woodland was at 1.472 with the new driver and 1.474 with the old driver.  Almost identical.  As for efficient transfer of energy, he doesn't seem to have lost anything at all with the older driver.  In fact he was a hair better with the old club.

That said, the carry distance with the old club wasn't nearly as proportional as the energy transfer, and seems surprisingly short with a 168 mph ball speed, doesn't it?   Did he happen to mention the ball flight/launch angle and spin?  I tried to duplicate Woodland's results on Bryan's Flightscope Optimizer website, and the only way I can get that short of a carry is with a really low launch and spin (9, 2100) or a really high spin (4800).
________________________________



.................................................



Added:  By the way, Jim, in thinking about the old patent applications where tests were performed outside on grass, it probably makes more sense to focus on carry distances, as roll is so variable with the conditions.

Here is a link to a Trackman article that explains smash factor.  Among other things he talks about the fine points of measuring clubhead speed.  Who knew that the toe has a higher speed than the heel so that optimal contact is 0.75 inches toward the toe.

trackmangolf.com/media/db865dec-50e0-439a.../3.../newsletter3.pdf‎


The Woodland smash factors are a little suspect.  There has been a very clear increase in COR's between wood drivers and trampoline effect titanium drivers - something like going from 0.7 to 0.83 iirc.

Interesting that the swing speed difference is 13 mph which is in line with the other examples we've found.  That should translate to 39 extra yards using the 3 yards/mph rule of thumb, not too far off the 48 yards measured.  Maybe the measurements were not quite accurate in the Woodland test.

Re outdoor tests, I read somewhere that the USGA spent a lot of time manicuring their outdoor range because of this concern.  Now, of course they do it indoors.

[Garland Bayley]

...
The Woodland smash factors are a little suspect.  There has been a very clear increase in COR's between wood drivers and trampoline effect titanium drivers - something like going from 0.7 to 0.83 iirc.

The COR went from either .78 or .79 to .83

[DMoriarty]

Bryan, to what are you referring when you say that as 13 mph is inline with other examples we've found? I was thinking around 7 mph was more in line with the rest of what we've found.  Padraig and Jeff reported 6 to 8 mph.  Here is another Andrew Rice experiment where he reports 7 mph.   http://www.andrewricegolf.com/2012/10/which-driver-shaft-length/  What are the other examples of 13?    

(Also keep in mind that an increase at the top end doesn't necessarily translate to the same increase at the bottom end, especially if we consider the yardage benefit.   Average golfers are much less likely to convert lighter and longer clubs into longer distances than top golfers.  Again, we see the technological benefits accruing mostly at the top.)

And, according to the Quintavalla study, I don't think the 3 yards rule of thumb is applicable for the extremely high swing speeds we are considering.  According to Quintavalla returns are diminishing fairly rapidly with each increased mph above 110 mph.  From 110-120 the average return is less than 110-120 the return is less than 2.5, and the report suggests that the bulk of the loss is at the high end, with even greater decline above 120 mph.  In Woodland's case, he is well above the range where a three yard gain per mph applies, so his total gain attributable to swing speed would be much less than 36 yards, wouldn't it?

Also, in Woodland's case, you suggest that the "smash factor" is suspect.  If the "smash factor" is suspect then either the swing speed or ball speed is wrong, which would seem to throw all the rest of the discussion of his numbers into question.  

As for COR, I think they were close to .78.   So the difference wouldn't be as great as you suggest.

Two inches longer in the shaft will get you about 5.5 yards according to this study.  

Going from a 120 gm shaft to a 65 gm shaft would get you 7.7 yards.

Thanks for the link.    

I understand what you are trying to say when you talk about what these changes to weight and length "will get you." But these are they kinds of "all-else-being-equal" tradeoffs that very rarely if ever apply to average golfers.  I think it is a pretty safe bet to say that most average golfers would be better off distance-wise with 44 inch drivers than 46 inch drivers, and that any gains in swing speed would be more than offset by increasingly poor ball striking.  

[Doug Siebert]

Tutleman's explanation of COR isn't too clear.  He says the COR of most balls were in the low .70s when the solid core ball was introduced (1970s?) and has maxed out at .79.  Then he starts in on the COR of the driver at 0.83.  Is the COR of the driver measured with steel?  So you have the ball COR on the one hand contributing, and the driver COR on the other hand contributing.  Then there's contribution from the lighter shaft and the longer shaft (this latter benefit mainly only holds due to the much larger clubface)

Regardless of the exact amount COR from the ball and from the driver contributes, it all amounts to a lot.  The exact amount each equipment factor benefits or the total amount it all benefits probably doesn't matter insofar as it seems to account for the observed increased to within the margin of error of all these various measurements.  There is no need to resort to claims that fitness or optimization had any meaningful contribution to the increases.  It has all pretty much been as a result of the equipment.

Can we all agree on that, or are some still convinced that factors aside from equipment made a significant contribution?  If we can agree on that, then we could move on to the question of what sort of changes to equipment would best put things back to how they were before (leaving the argument over question of "should we make those changes" for last)

[Patrick_Mucci]

Bryan,

I'd be cautious when reviewing swing studies from the 60's and 70's as I don't think there was a keen awareness of launch angles, which could have an impact on carry and overall distance.

In addition, "spin" was a material factor in the 60's and 70's as balls hit with high speeds would rocket out, low, then balloon up to their apogee/apex , then fall sharply without much roll.

Ball flight in the 60's and 70's was significantly different from today, especially with off center hits and deviant swings.