[Bryan Izatt]

Here s a ball test from 2001 using TopFlite, Tour Balata and ProV1 amongst others.  It was conducted with a 7 iron, so presumably no more than 80 mph swing speed.  The smash factors were in the high 1.3's.  Anybody want to try to scale this up for drivers?

The TopFlites were 5.3 yards longer than the Tour Balata.  The ProV1 was 4.5 yards longer than the Tour Balata and 0.8 yards shorter than the TopFlites.  The Professional was essentially the same distance as the Tour Balata.

http://www.equip2golf.com/tests/tests_frameset.html?golf_ball_reports/irons_report.html~tests

[DMoriarty]

Looking at the tour data: the Pro Vi breed of golf ball is about 8-10 yards longer than the balata/wound ball, so comparable to the difference between balata and Top Flite in the study (for that range of swing speeds at least).

So your chart has the longest 10%  gaining 17-18 yards from 2000 to 2005, and from that you determine that the ProV1 breed of ball is 8-10 yards longer?   That is some interesting math.
___________________________________

Bryan,

Do you really think that there is any way to reasonably scale those numbers up to a driver?  I have my doubts.  Isn't the idea behind the new balls that they are supposed to be low spin off the driver but high spin off the short iron?  If the balls have inconsistent spin profiles, I have trouble understanding how these numbers are meaningful.

[Paul_Turner]

David

Why pick 2005 and not 2010? The sensible number to choose would the average of 2003-2013 which gives 13 yards gain from 2000.  And then of course the driver was going through significant changes 2000.  Subtract about 5 yards for the driver and it's effect in increasing the COR of the ball club energy transfer.

[Mark Bourgeois]

Tom Paul speaks:

Does it appear to the participants on this thread that David Moriarty or anyone else is suggesting there should be a consistent yardage distance increase (decrease) differential across the entirety of some swing speed spectrum (ie 80mph---120mph) with all conforming clubs and balls, or even a particular ball such as the ProV1 and ProV1x type? If so, does it occur to the participants that there is, and always has been, a huge amount of different product inventory of both clubs and balls that are listed within the USGA lists of Conforming clubs and balls? (about 2,000 different balls and hundreds of different clubs on the Conforming Lists). Therefore, it would probably be completely unworkable to ever expect them all, and for all combinations of clubs and balls, to produce some consistent distance differential across some swing speed spectrum of golfers. Within the USGA Conforming club and ball inventory it is up to any golfer to find whatever combination of club and ball works best for his or her game. It has always been that way in golf. Why has it always been that way in golf? Probably because, unlike most every other stick and ball game, golf may be the only stick and ball game of major size worldwide in which the ball is neither common nor vied for between participants----eg the fundamental format and Rules of the game prevent it.

[Bryan Izatt]

David,

No, I don't think the numbers can be reasonably scaled up for a driver, but I thought someone else might want to try it.


The TopFlite spun about 1500 rpm less than the Tour Balata.  The ProV1 spun about 1000 rpm less than the Tour Balata, but 500 rpm more than TopFlites.  These results seem consistent with the common perceptions about the relative playabilities of the TopFlites, Tour Balatas and ProV1s.

I suspect that the relative spin rates would be maintained with a driver.

My point in the post above was to address the relative length of the ProV1 vs the TopFlites.  With a 7 iron, the TopFlites are a bit longer than the ProV1.  I see no reason this wouldn't also be true with drivers.  I thought this addressed some of the previous debate about whether the ProV1 was longer than the TopFlites.

Since you seem to be good at finding patents, have you found any from, say 1999 to present where ball manufacturers have patented any new core material that significantly improved the COR of the core.  I believe the two-piece balls were using polybutadiene back before the ProV1.  Has there been a move to higher COR materials in the last 15 years?

[DMoriarty]

Paul Turner, with respect, I don't think it is at all "sensible" to pretend you can come up with an exact number representing the technological advancement in the ball based on some tour stat averages, and it is even less "sensible" to pretend that whatever number you come up with provides you a meaningful point of comparison with the controlled conditions of a lab test.  There are too many other things going on here, including the inclusion of plenty of non-drivers and babied drivers in your tour averages.

The tour stats give us nice general indication of the timing and a very rough idea of the relative magnitude of the gains, but beyond that you seem to be just making things up.  For example you attribute 5 yards to the driver, but this seems to be a made up number to me, especially since the COR limit was already in place during the period you are examining.  Likewise your ending date seems to be made up to minimize the significance of the gains.  That the total distance has dropped indicates that there is more going on here than just the technological changes (because the technology certainly didn't regress) but you ignore this and pretend that the later date is somehow more indicative of the technological change than the earlier date.  This too seems to be driven at achieving a desired result.  

If you insist on using the tour stats then it seems to be that the "sensible" approach would be to try to find numbers where the greatest number of factors other than the ball are closer to controlled, which would suggest looking at a shorter period of time, rather than a longer period of time.   I used 2000--2005 because 2000 was the year before the ProV1, and 2005 was after the ProV1x and after other ball manufacturers had a chance to respond with comparable ball technology.   My intent was to come as close as possible to eliminating other variables of which they are many.  My numbers are seriously flawed because some players had already switched to the modern ball before 2000, and because there were other changes going on during the period, and because the whole idea of using averages for this sort of thing just doesn't really work for reasons I have discussed before. (For example the apparent movement away from using driver on traditional driver holes by longer hitting tour pros.) Nonetheless, despite the shortcomings, the narrower time period certainly makes more sense than your longer averaging approach.  A better way would be to look at individual golfers active from 2000 to 2005 and look at the gains they individually made during this time period, and to try to correlate that with equipment changes.  I tried this approach years ago with the ProV1x and some of those numbers are available somewhere above.  

[DMoriarty]

David,

No, I don't think the numbers can be reasonably scaled up for a driver, but I thought someone else might want to try it.

Bryan, had you stopped there, we'd be in agreement.  But then you go on to say that you can't see any reason why the differences with a seven iron numbers wouldn't hold true with drivers. This makes no sense to me given that you agree that the numbers cannot be reasonable scaled up for drivers. The reason we cannot conclude the numbers would hold true with a driver are the same as why the numbers cannot be scaled up. The balls don't necessarily behave the same with a seven iron as they do with a driver, which was the whole point of the new balls, wasn't it? Looking again at the numbers, I don't see how you could possibly scale up, which is what you are trying to do with your statement about drivers whether you acknowledge it or not.

I don't think any of the numbers are necessarily relevant to what happens with a driver, but the "smash factor" numbers definitely don't support your supposition about drivers. Smash factor is supposed to be a measure of how efficiently energy isl transferred from swing speed to ball speed.  The ProV1 had higher "smash factor" numbers than 37 of the 40 balls. Titleist's new distance ball (the DT distance, one of the replacements for the discontinued wound DT)  had a slightly higher smash factor, but this ball likely incorporated some of the same technology as the ProV1, don't you think?  (The other ball with a higher smash factor was a "Wilson SC Distance." Wasn't Wilson one of the companies (along with Bridgestone) who supposedly beat Titleist to the punch with supposed ProV1-type technology?)

[DMoriarty]

Bryan, Along the same lines of my comments about smash factor, the height of the shots also indicates that there might be something different going on in that test with the ProV1.  The ProV1 had a higher peak height than all the balls but one (again the Wilson SC distance.) The ProV1 appears to be reacting differently that what might be the traditional harder balls like the Top Flite. (Hard to say because this was 2001 and we don't know what changes were being made to these balls as compared to, say, a 1980 Top Flite.)

Wasn't the playability of the ProV1 supposed to be much improved over the Top Flite type balls, but still supposedly different than the Balata?  Namely with irons weren't they supposed to fly higher and come down softer?  Whereas the balata was supposed to come down with more spin?

[Padraig Dooley]

Ball speed is still creeping up every year on tour.

[Bryan Izatt]

David,

No, I don't think the numbers can be reasonably scaled up for a driver, but I thought someone else might want to try it.

Bryan, had you stopped there, we'd be in agreement.  But then you go on to say that you can't see any reason why the differences with a seven iron numbers wouldn't hold true with drivers. This makes no sense to me given that you agree that the numbers cannot be reasonable scaled up for drivers. The reason we cannot conclude the numbers would hold true with a driver are the same as why the numbers cannot be scaled up.

By scaled up I meant that we couldn't say the driver difference between the Tour Balata and the Topflites would be precisely 10 yards when the 7 iron difference was measured at 5.3 yards.  I am of the opinion that the relative differences shown for the 7 iron would hold true for the driver.  In this case, the 7 iron distances of the ProV1 and the Topflites are about the same.  I expect that that would have held true for the driver as well.  I don't think tere is some mysterious force that is going to skew the results with the driver compared o the 7 iron.  You seem to think otherwise, and that's fine.

The balls don't necessarily behave the same with a seven iron as they do with a driver, which was the whole point of the new balls, wasn't it?

I'm not sure what you mean by "behave the same".  The ProV1 was designed to have a Topflite-type COR core and a cover that didn't cut and provided spin for wedges.  There is no reason to think that the ProV1 would "behave" differently than a TopFlite off a driver other than likely have somewhat more spin.  As discussed above, spin within reason off the driver is not all that significant to driver distance.  Even Garland is now a believer.

Looking again at the numbers, I don't see how you could possibly scale up, which is what you are trying to do with your statement about drivers whether you acknowledge it or not.

My definition of scaling up was to try to put numbers on it.  I believe that if the ProV1 and Topflite went similar distances with a 7 iron they would go similar distances with a driver.  If you think otherwise could you tell me what factor would cause the difference and which one would go further.

I don't think any of the numbers are necessarily relevant to what happens with a driver, but the "smash factor" numbers definitely don't support your supposition about drivers. Smash factor is supposed to be a measure of how efficiently energy isl transferred from swing speed to ball speed.  The ProV1 had higher "smash factor" numbers than 37 of the 40 balls.

I wasn't comparing the ProV1 to 37 other balls, just to the TopFlites and to demonstrate that topFlites and ProV1's went the same distance more or less.  The smash factors for the balls I was referring to were different by an infinitesimal 0.006.  We can't agree on one ball, why get into debates on the other balls.

Titleist's new distance ball (the DT distance, one of the replacements for the discontinued wound DT)  had a slightly higher smash factor, but this ball likely incorporated some of the same technology as the ProV1, don't you think?  (The other ball with a higher smash factor was a "Wilson SC Distance." Wasn't Wilson one of the companies (along with Bridgestone) who supposedly beat Titleist to the punch with supposed ProV1-type technology?)

[Bryan Izatt]

Bryan, Along the same lines of my comments about smash factor, the height of the shots also indicates that there might be something different going on in that test with the ProV1.  The ProV1 had a higher peak height than all the balls but one (again the Wilson SC distance.) The ProV1 appears to be reacting differently that what might be the traditional harder balls like the Top Flite. (Hard to say because this was 2001 and we don't know what changes were being made to these balls as compared to, say, a 1980 Top Flite.)


I was focused on the TopFlites not all the other balls.  The ProV1 peaked at less than 2 feet higher than the TopFlites - probably not statistically significant. How is that the ProV1 reacting differently? 

The other balls are generally within 5 feet or 4% of the ProV1 peak.  Is that really significant?



Wasn't the playability of the ProV1 supposed to be much improved over the Top Flite type balls, but still supposedly different than the Balata?  Namely with irons weren't they supposed to fly higher and come down softer?  Whereas the balata was supposed to come down with more spin?

No, the ProV1s were supposed to spin more the 2-piece balls with short irons and thus stop more quickly than a ball with a Topflite-like COR core.  As it turned out they spun less than Tour Balatas.  I have no idea if that was by design or was just a compromise to get the driver COR numbers they wanted with as much spin as they could get out of a new cover and mantle.

[Bryan Izatt]

Mark (Tom Paul),

Short answer - I don't think anybody is arguing that there is a single distance/swing speed curve slope.  Several pages back I posted a graph of 4 studies that clearly show different slopes.  It is intuitively obvious that ever ball/club combination could be somewhat different.  I for one don't think the slopes are radically different, but they are probably different.

[Bryan Izatt]

Ball speed is still creeping up every year on tour.

More faster swingers on Tour - it continues to be a power game?

[Bryan Izatt]

David,

For example the apparent movement away from using driver on traditional driver holes by longer hitting tour pros.

Do you have any data to back this up?  Do you know which holes are driving measurement holes each week and what club each player used?

[DMoriarty]

Your recollection of what the ProV1's were supposed to do is different than mine, and I don't think it was quite as simple as combining distance characteristics from one ball type and spin from another ball type. The control provided with short irons by the ProV1 wasn't the same as with the Balata, which had more spin and less height. And the distance characteristics provided by the ProV1 off the tee wasn't the same as with the old Rock Flites, which flew lower and rolled more. In both instances, I think the modern balls generally had a higher launch and more carry.

Regarding your analysis of this study, you seem to be cherry picking some stats while ignoring others. You say that, "There is no reason to think that the ProV1 would "behave" differently than a TopFlite off a driver other than likely have somewhat more spin." Well, they weren't at all the same ball, so I don't think there is any reason to expect they would "behave" identically or even similarly. You think they launched identically, with the driver?  Based on what? You think they had a similar shape of trajectory? Based on what? What makes you think the spin difference with a 7 iron is applicable to a driver?

The respective ball behaviors off a driver aren't "mysterious forces" but they are certainly relevant to distance and I see absolutely no reason why we would simply assume those two different balls would behave identically or even similarly. As you noted, these things are pretty complicated.  And IMO it is a gross oversimplification to say that the ProV1 had the control of a balata and the distance of a Top Flite.

As for whether the height difference and "smash factor" numbers are statistically significant, I don't think any of the 7 iron numbers, including the numbers on which you are relying, are statistically significant when discussing driver distances.    

With respect Bryan, it really seems you are grasping at straws on this one. Imagine what your reaction would be if I or anyone else produced a similar study where the ProV1 was a couple of yard longer, and then tried to conclude that this means that the ProV1 was an equal percentage longer with a driver.
_________________________________________

Do you have any data to back this up?  Do you know which holes are driving measurement holes each week and what club each player used?

I think that generally they try to choose two holes where players will generally hit driver, but at some of these courses I don't think that there are many holes left where all the golfers must hit driver to be in the hole.

[Mark Bourgeois]

From Tom Paul:

Bryan Izatt:

Thank you for your reply. A week or two ago I read this thread and noticed that the suggestion was made that the USGA should ban the ProV, ProVx type ball technology. I suppose that suggestion means all balls that have combined the distance technology of the old lower spin rate two piece hard cover type ball and the softer "feel" technology of the old higher spin rate "balata" type technology. The reason given on this thread for that suggestion (beginning with #117 and #122 et al) was that this new ball technology in the last 10-20 years has only benefited the high swing speed players with increased distance and not low swing speed players, or at least not commensurately. By the way, for those participants interested in researching and investigating the history and evolution of this golf "technology" subject, there is a quite interesting 38 page presentation on the Titleist website entitled "Technology and Tradition---Preserving the Balance." I suppose some will agree with most of what it says, and others may disagree with some of it, perhaps citing the fact the presentation was produced by a prominent I&B manufacturer and therefore somewhat self-serving and perhaps not completely or factually accurate. From my own experiences playing a ton of Class A (scratch) amateur golf tournaments annually from about 1978 to about 2005, it looks pretty accurate to me. The specific aspect of ball performance of the old higher spin rate balata type technology with really high swing speed players that always fascinated me was the odd initially low (for a hundred or so yards) to swiftly climbing trajectory they put on those higher spin rate balata type balls, particularly with their driver. I thought it was such a beautiful flight (trajectory). It was not until the late 1990s or 2000s that I was told by some equipment scientists, including within and around the USGA Research and Test Center data,* that that particular trajectory could lose really high swing speed players +or- 30 yards in carry distance compared to the solid core "distance" technology that ironically only less talented and lower swing speed players seemed to use in the 1980s and early 1990s (and I suppose also compared to the new age ball technology that apparently relied on a much lower spin rate than the old "balata type" ball technology that basically most all Class A golfers used to use before the appearance and improvement to the so-called "new age" ball.

*How and why it seemed only those really high swing speed players could generate that fascinating trajectory with high spin rate "balata" type technology is a scientific/physics/aerodynamic question which is probably beyond my own purview to completely understand. And, for another "by the way," there are a few interesting articles also on the Titleist website entitled something like "the myths of ball performance" that may help participants to understand this seemingly aerodynamic phenomenon of certain types of ball performance by certain types of players (in this case excessively high swing speed players). Personally it seems to me it may have had to do with an excessive amount of "drag" behind the ball only really high swing speed players can generate, apparently due to some combination of excessive ball speed AND excessive spin rate (rpms, as well as apparently an unusually high differential of high and low pressure between the front and back of the ball) that creates excessive turbulence within the so-called "boundary layer" of air flow turbulence around and behind the ball. There is even a drawing of this excessive "drag" boundary layer behind the ball in one of those articles on the Titleist website. It appears that this excessive "drag" behind the ball might be what keeps the ball down in a low or flat initial trajectory before and until enough turbulence ("drag") dissipates behind the ball where the "boundary layer" turbulence behind the ball can begin to tuck in nicely around the back of the ball in flight-----at which point the ball climbs rapidly into a much higher final trajectory (which I suppose makes aerodynamic sense since spin rate or air flow turbulence around a flying object does create "lift" or at least so long as there is not too much "drag" behind the flying object

[Paul_Turner]

David
There is obviously random up and down variation from year to year in the tour stats.  The flat periods show this and it was apparent in the 1980s/ early 1990s too before the steady trend upwards.  So it's more informative to pick an average of several years during this flat period rather than a single year which is vulnerable to this random fluctuation.  I do not believe tech has changed significantly in the last 10 years.

I don't agree that the driver was "maxed out" by 2000, the COR limit was in place but that doesn't necessarily mean all manufacturers had reached that limit and there was still plenty of work going on in optimizing the position of the Center of Gravity/Percussion which still tended to be too high in the club and is critical for getting the launch angle correct.  See The "How Golf Clubs Really Work" book I referenced earlier which shows the importance of this parameter:  they compare a 1999 driver with an optimized driver and the difference is about 5 yards.

Tour stats are messier than a lab but are certainly useful for comparing periods and I don't think there's been a significant change in the percentage of drivers being used on the holes measured for distance on tour.  The R&A reported 90% as the figure.   I don't think there's any evidence that players are hitting more "babied drivers" than in the past the opposite is often suggested, that players can now swing harder with impunity due to larger more forgiving club heads.

Interestingly, The R&A do claim that drivers are much more in use now for the average golfer than 15 or so years back.

[DMoriarty]

Paul,

You can't compare average tour stats to lab tests.  There are too many variables entered into the average (3 woods or irons off the tee, mishits, balls in rough, babied drivers, etc.)  Tour stat averages don't even come close to capturing ball performance of balls struck solidly by guys with their normal swing speed.  Your assertions about  how often they hit driver don't seem to reflect the reality of their games so far as I am concerned. Trends change in golf along with the equipment, and as holes get relatively shorter as compared to how far they hit the ball, the long hitters will hit  driver less, because on many holes it just doesn't make sense to try and drive it 330-340.  

According to the pgatour website, Bubba Watson's driving distance was only 303 yards, on 145 measured drives. Yet his "average" driver swing speed on 52 measured swings was 125 mph, and his average ball speed on these 52 measured swing was over 182 mph.  Those numbers don't jibe with his driving average on measured drives.  According to any simulation or chart or guideline, he is producing way too much ball velocity to only be averaging 303 yards with the driver.  Add in his average spin figures and trajectory, and he ought to be hitting it far beyond this, on average.   Watching him play confirms this.  His normal drives under normal condition normally travel far beyond the 303 yard figure.   The 303 yard figure, as absurdly high as it is, doesn't even come close to capturing his (or his equipment's) performance off the tee.

[JESII]

David,

What would be the ideal test or experiment for you to have full clarity into this issue?

[Paul_Turner]

David

Bubba had a down year in 2013.  Bubba's average stats for earlier years are often in the 310-315 range which match up with 185 ball speed, unless you think he was swinging even harder in those years, or electing to use driver more.

Of course the average driving distance will be pulled down with 3 woods etc but this would have been true for earlier periods too.

 

[Bryan Izatt]

Mark/Tom Paul,

As simply as I can, here is why your favored ball flight happened.

After a ball is launched, it has forward momentum at whatever launch angle was imparted by the club/ball collision.  There are three other forces at work.  Drag forces that want to slow the ball down.  Gravity acting on the weight of the ball that wants to cause the ball to drop.  And, the Magnus force caused by the backspin on the ball that wants to create lift to cause the ball to go up.  Below is a graphic representing this.

The Magnus force is what causes lift on wings enabling airplanes to fly.  It is also the force which causes baseballs to curve.  For golf ball and baseball curves, the faster the spin the greater the Magnus force.

Iniially the forward momentum of the ball overcomes the lift and gravity forces so you get a straight flight.  Eventually the drag slows the ball down to a point where the lift and gravity forces start to take over.   In the old tour balata days the ball spun so fast that the lift exceeded the gravity force to the extent that the ball rose to a peak until the spin bled off and gravity took over.

There's no mystery, it's basic physics. 

I think back in the day we all liked that trajectory because we just didn't know any better and the high spin rate enabled by the Tour Balata and the high spin loft of swings and drivers of that era.




If you're interested here is another image that describes spin loft.  The higher the spin loft of your swing with your driver, the more spin will be imparted to the ball.

[Bryan Izatt]

David,

Your assertions about  how often they hit driver don't seem to reflect the reality of their games so far as I am concerned. Trends change in golf along with the equipment, and as holes get relatively shorter as compared to how far they hit the ball, the long hitters will hit  driver less, because on many holes it just doesn't make sense to try and drive it 330-340.

I understand that this is your view.  But, you seem to have no actual data to support it.

If using tour averages is bad, then using one player, Bubba, is worse.

It is possible that there is potential for tour players to gain more distance than their tour averages suggest.  But, you discount the same potential in "average" players.  For tour players it might be course management related.  For average players it might be a lack of skill to achieve optimal conditions on a consistent basis. 


______________________________________


On the ball "behaviour" front, I'm still trying to understand how you think different balls behave differently.  Suppose we create a hypothetical scenario where a robot is set up in a controlled environment to have a repeatable swing speed, angle of attack, dynamic loft and spin loft and hits two balls - the ProV1 and the TopFlite.  And, we compare the results of multiple repetitions of the test for each ball.  What aspects of the ball launch and trajectory do you think would be different? What forces would be at work to produce the different behaviours?  What parts of the composition of the ball would affect the behaviour and why?

[Doug Siebert]

From Tom Paul:

Bryan Izatt:

Thank you for your reply. A week or two ago I read this thread and noticed that the suggestion was made that the USGA should ban the ProV, ProVx type ball technology. I suppose that suggestion means all balls that have combined the distance technology of the old lower spin rate two piece hard cover type ball and the softer "feel" technology of the old higher spin rate "balata" type technology. The reason given on this thread for that suggestion (beginning with #117 and #122 et al) was that this new ball technology in the last 10-20 years has only benefited the high swing speed players with increased distance and not low swing speed players, or at least not commensurately. By the way, for those participants interested in researching and investigating the history and evolution of this golf "technology" subject, there is a quite interesting 38 page presentation on the Titleist website entitled "Technology and Tradition---Preserving the Balance." I suppose some will agree with most of what it says, and others may disagree with some of it, perhaps citing the fact the presentation was produced by a prominent I&B manufacturer and therefore somewhat self-serving and perhaps not completely or factually accurate. From my own experiences playing a ton of Class A (scratch) amateur golf tournaments annually from about 1978 to about 2005, it looks pretty accurate to me. The specific aspect of ball performance of the old higher spin rate balata type technology with really high swing speed players that always fascinated me was the odd initially low (for a hundred or so yards) to swiftly climbing trajectory they put on those higher spin rate balata type balls, particularly with their driver. I thought it was such a beautiful flight (trajectory). It was not until the late 1990s or 2000s that I was told by some equipment scientists, including within and around the USGA Research and Test Center data,* that that particular trajectory could lose really high swing speed players +or- 30 yards in carry distance compared to the solid core "distance" technology that ironically only less talented and lower swing speed players seemed to use in the 1980s and early 1990s (and I suppose also compared to the new age ball technology that apparently relied on a much lower spin rate than the old "balata type" ball technology that basically most all Class A golfers used to use before the appearance and improvement to the so-called "new age" ball.

*How and why it seemed only those really high swing speed players could generate that fascinating trajectory with high spin rate "balata" type technology is a scientific/physics/aerodynamic question which is probably beyond my own purview to completely understand. And, for another "by the way," there are a few interesting articles also on the Titleist website entitled something like "the myths of ball performance" that may help participants to understand this seemingly aerodynamic phenomenon of certain types of ball performance by certain types of players (in this case excessively high swing speed players). Personally it seems to me it may have had to do with an excessive amount of "drag" behind the ball only really high swing speed players can generate, apparently due to some combination of excessive ball speed AND excessive spin rate (rpms, as well as apparently an unusually high differential of high and low pressure between the front and back of the ball) that creates excessive turbulence within the so-called "boundary layer" of air flow turbulence around and behind the ball. There is even a drawing of this excessive "drag" boundary layer behind the ball in one of those articles on the Titleist website. It appears that this excessive "drag" behind the ball might be what keeps the ball down in a low or flat initial trajectory before and until enough turbulence ("drag") dissipates behind the ball where the "boundary layer" turbulence behind the ball can begin to tuck in nicely around the back of the ball in flight-----at which point the ball climbs rapidly into a much higher final trajectory (which I suppose makes aerodynamic sense since spin rate or air flow turbulence around a flying object does create "lift" or at least so long as there is not too much "drag" behind the flying object

Mark, if you would be so kind as to forward this to Tom, I have a couple questions for him regarding this post.

I actually disliked that initial flat to climbing trajectory, since I had higher launch than most so it would really get up there (which I "mostly" fixed by using a 6.5* driver)  It was a real problem into a strong wind, I was able to hit my 1 iron further into a 25 mph wind than I could hit my driver when using a Tour Balata.  I remember buying a dozen Maxfli STs in St. Andrews halfway through my first visit to Scotland because my balatas were proving to be a problem in the wind over there!

The huge difference in the trajectory of a driver hitting a balata versus hitting a modern ball, even though the launch monitor results seem to indicate that the initial spin rates are very similar, makes it pretty obvious that "something is going on here".  So I'm still really interested in learning more about any studies/measurements of spin decay rates (downrange spin) in old balls (both balata and Rock Flite) and the modern ball as a source of this difference.  How much has the USGA investigated this?  Do they think this is an important difference, or has it been checked and discarded?  If so, what do they believe accounts for the large difference in trajectory with the modern ball?

While I haven't done it recently, in the early years of the Pro V1 and V1x I used to get my trusty old persimmon out and hit some drives with it to compare.  Since it had more loft than the modern driver(s) I used at the time, the trajectory was similar to when I hit the ball high on the face of the modern driver - I also got pretty much the same distance I'd get on one of those shots (about 275 yards carry, which I very very rarely managed with a balata in flat/windless conditions)  Based on that experience, I would expect that if it were possible to get a "new" (rather than 15 year old dried out husk) balata I'd have produced that classic balata low(ish) initial trajectory that really shot up downrange even with a modern driver.  I can no longer do such experiments though, somehow that old persimmon driver has become heavier and the shaft quite a bit stiffer in the last few years

I'm also wondering if the USGA has any figures or has done any measurement of the moment of inertia of modern balls versus the old balls?  i.e. have they moved more weight towards the center of the ball, so that it loses spin more quickly?  There may be other ways to create such an effect, but that's sort of my working theory at the moment.  Unfortunately, without any data I don't have any way to know if I'm on the right track or barking up the wrong tree.

[DMoriarty]

David

Bubba had a down year in 2013.  Bubba's average stats for earlier years are often in the 310-315 range which match up with 185 ball speed, unless you think he was swinging even harder in those years, or electing to use driver more.

I suspect the latter.

Of course the average driving distance will be pulled down with 3 woods etc but this would have been true for earlier periods too.

The game has changed drastically over this time period, and you cannot simply assume the rate has stayed constant just because it suits you.

[DMoriarty]

I understand that this is your view.  But, you seem to have no actual data to support it.

Paul is the one trying to compare tour averages to the controlled conditions of a lab test.

If using tour averages is bad, then using one player, Bubba, is worse.

It is not just Bubba. Check the stats of others and you'll see that the ball speed stats don't seem to fit for the measured distance stats.

Or look at the "average ball speed" Padraig posted above. Trackman has the ball speed rising about 2 mph from 2011-2013, yet Paul has the average distance decreasing by around 5 yards during the time period.  Since when do higher ball speeds produce significantly shorter drives?   According to Trackman, since 2009 average ball speed has increased 4.5 mph, but Paul says there has been no net gain in distance during this time period.    The tour averages aren't reliably reflecting what is going on with the driver.  

It is possible that there is potential for tour players to gain more distance than their tour averages suggest.  But, you discount the same potential in "average" players.  For tour players it might be course management related.  For average players it might be a lack of skill to achieve optimal conditions on a consistent basis.

It is not "potential" for the tour players.  The are choosing to lay-back.  You aren't seriously equating the lack of skill and ability of an average player with Bubba's choice to hit a 300 yard 3 Wood rather than  340 yard driver, are you?   If you are, give me a break.  

As for the average player, I "discount" potential for average players because it is a fiction.   You can't treat an 85 mph swinger like a 95 mph swinger because theoretically maybe some day he'll improve.  He won't.  And if he did, he would no longer be an average player!

Like I said to Jim, if it makes you feel better, focus only on well struck shots for each group.  My ideas remain the same.  
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On the ball "behaviour" front, I'm still trying to understand how you think different balls behave differently.  Suppose we create a hypothetical scenario where a robot is set up in a controlled environment to have a repeatable swing speed, angle of attack, dynamic loft and spin loft and hits two balls - the ProV1 and the TopFlite.  And, we compare the results of multiple repetitions of the test for each ball.  What aspects of the ball launch and trajectory do you think would be different? What forces would be at work to produce the different behaviours?  What parts of the composition of the ball would affect the behaviour and why?

They are different balls, Bryan.  With different covers, layers, materials, dimple patterns, compression characteristics, etc.   They will behave differently in a controlled test.  Different spin rates, different launch angles,  different trajectory, different apex point, different initial velocity, different carry, different distance, different roll.   You really don't get why I think they would perform differently in some respects on a launch monitor?

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