Question for club fitters - do you consider the difference between grass and mats in iron fitting?

golfer55082 · November 12, 2019

Hi I have a question for club fitters on this forum: when you perform iron fittings for your customers, do you generally take into account the difference between real grass and hitting mats in deciding the right shaft? I say this because it is generally agreed that a hitting mat would promote a lower back spin and higher launch angle when hitting an iron vs. real grass. One resource finds that for a 7 iron, hitting from mats will launch 1000 rpm lower and 3-4 degrees higher. Therefore, if a person hits his 7 iron at 6000 rpm back spin with 19 degree launch angle off hitting mats, his number may become 7000 rpm in back spin and 16 degree in launch angle if he hits from real grass, both close to optimal numbers.

Does this make sense?

Howard_Jones · November 12, 2019

> @golfer55082 said:

> Hi I have a question for club fitters on this forum: when you perform iron fittings for your customers, do you generally take into account the difference between real grass and hitting mats in deciding the right shaft? I say this because it is generally agreed that a hitting mat would promote a lower back spin and higher launch angle when hitting an iron vs. real grass. One resource finds that for a 7 iron, hitting from mats will launch 1000 rpm lower and 3-4 degrees higher. Therefore, if a person hits his 7 iron at 6000 rpm back spin with 19 degree launch angle off hitting mats, his number may become 7000 rpm in back spin and 16 degree in launch angle if he hits from real grass, both close to optimal numbers.

>

> Does this make sense?

>

Short answer is yes, but 3 to 4 higher is way more than i ever heard of, but it is correct that launch is higher and spin is lower from a mat vs turf, but that vary both depending on the mat itself, the turf we compare it to, and the players angle of attack, so there is no constant conversion factors here. Trackman did a test with a player and launch was just below 3 higher, and spin just below 2000 lower, but again, it depends on many different factors.

https://blog.trackmangolf.com/mats-vs-grass-whats-difference/

mbarnocki · November 12, 2019

Crap, really 2000 spin more? I just got fit this weekend and bought some irons i was launching at 20* and spinning 6800 on the 7 iron demo. Now I think launch will be fine but spin will be too high.

Howard_Jones · November 12, 2019

TXG did a similar test, but with hardly no difference, and that tells us that both the mat itself and the turf we compare it to will always vary

Their numbers was about 0,5 higher launch from the mat, and a spin level that was only 70 rpms in difference

If you now move to the typical sim forums, you will again see different numbers.....

So the club fitter better know how HIS mat works....i used 1* on launch and 800 rpms as "average" or expected difference.

BB28403 · November 13, 2019

> @"Howard Jones" said:

> TXG did a similar test, but with hardly no difference, and that tells us that both the mat itself and the turf we compare it to will always vary

> Their numbers was about 0,5 higher launch from the mat, and a spin level that was only 70 rpms in difference

>

> If you now move to the typical sim forums, you will again see different numbers.....

>

> So the club fitter better know how HIS mat works....i used 1* on launch and 800 rpms as "average" or expected difference.

>

But doesn’t TXG do ALL their fittings on Mats. So you kind of have to wonder, what’s their motivation?

If they said “oh crap, grass is better than mats!” Then all of their studios would have to be moved outside.... Just saying

Z1ggy16 · November 13, 2019

> @BB28403 said:

> > @"Howard Jones" said:

> > TXG did a similar test, but with hardly no difference, and that tells us that both the mat itself and the turf we compare it to will always vary

> > Their numbers was about 0,5 higher launch from the mat, and a spin level that was only 70 rpms in difference

> >

> > If you now move to the typical sim forums, you will again see different numbers.....

> >

> > So the club fitter better know how HIS mat works....i used 1* on launch and 800 rpms as "average" or expected difference.

> >

>

> But doesn’t TXG do ALL their fittings on Mats. So you kind of have to wonder, what’s their motivation?

> If they said “oh crap, grass is better than mats!” Then all of their studios would have to be moved outside.... Just saying

Ian doesn't seem like the kind of guy who would purposely lie and deceive viewers. I've been to TXG and everybody there was super nice and in general, they all seemed like outstanding people. And I feel like it's not a deal of one is "better" than another because as Howard said, there is no single factor or way to convert between the two. For Matt, the grass there vs the mat they used with him, made no big differences.

@"Howard Jones" would you say perhaps it makes a larger difference for players who tend to hit a little more down on the ball, or play on softer turf? If you're pretty shallow and/or hit off firmer turf... you have less ground interaction overall, no?

BB28403 · November 13, 2019

> @Z1ggy16 said:

> > @BB28403 said:

> > > @"Howard Jones" said:

> > > TXG did a similar test, but with hardly no difference, and that tells us that both the mat itself and the turf we compare it to will always vary

> > > Their numbers was about 0,5 higher launch from the mat, and a spin level that was only 70 rpms in difference

> > >

> > > If you now move to the typical sim forums, you will again see different numbers.....

> > >

> > > So the club fitter better know how HIS mat works....i used 1* on launch and 800 rpms as "average" or expected difference.

> > >

> >

> > But doesn’t TXG do ALL their fittings on Mats. So you kind of have to wonder, what’s their motivation?

> > If they said “oh crap, grass is better than mats!” Then all of their studios would have to be moved outside.... Just saying

>

> Ian doesn't seem like the kind of guy who would purposely lie and deceive viewers. I've been to TXG and everybody there was super nice and in general, they all seemed like outstanding people. And I feel like it's not a deal of one is "better" than another because as Howard said, there is no single factor or way to convert between the two. For Matt, the grass there vs the mat they used with him, made no big differences.

>

> @"Howard Jones" would you say perhaps it makes a larger difference for players who tend to hit a little more down on the ball, or play on softer turf? If you're pretty shallow and/or hit off firmer turf... you have less ground interaction overall, no?

But Trackman has nothing to gain or lose by doing the test. They just want their equipment to be respected .

On the other hand, just like I said. If grass was better then TXG has ALOT to lose. They are a business. Not saying that they aren’t nice guys. But if you had millions on the line, would you let it out that grass is better? Nahhhh of course you wouldn’t .

Just playing devils advocate . I know there are lots of team TXG’ers here! They are quite entertaining .

shot-savior · November 13, 2019

Beyond spin and launch discrepancies, how does one expect to evaluate how an iron's sole will interact with real turf when hitting off a mat? One must really be outdoors, in condition, to properly evaluate a club's performance. I've got to see that ball fly.

Z1ggy16 · November 13, 2019

> @BB28403 said:

> > @Z1ggy16 said:

> > > @BB28403 said:

> > > > @"Howard Jones" said:

> > > > TXG did a similar test, but with hardly no difference, and that tells us that both the mat itself and the turf we compare it to will always vary

> > > > Their numbers was about 0,5 higher launch from the mat, and a spin level that was only 70 rpms in difference

> > > >

> > > > If you now move to the typical sim forums, you will again see different numbers.....

> > > >

> > > > So the club fitter better know how HIS mat works....i used 1* on launch and 800 rpms as "average" or expected difference.

> > > >

> > >

> > > But doesn’t TXG do ALL their fittings on Mats. So you kind of have to wonder, what’s their motivation?

> > > If they said “oh crap, grass is better than mats!” Then all of their studios would have to be moved outside.... Just saying

> >

> > Ian doesn't seem like the kind of guy who would purposely lie and deceive viewers. I've been to TXG and everybody there was super nice and in general, they all seemed like outstanding people. And I feel like it's not a deal of one is "better" than another because as Howard said, there is no single factor or way to convert between the two. For Matt, the grass there vs the mat they used with him, made no big differences.

> >

> > @"Howard Jones" would you say perhaps it makes a larger difference for players who tend to hit a little more down on the ball, or play on softer turf? If you're pretty shallow and/or hit off firmer turf... you have less ground interaction overall, no?

>

> But Trackman has nothing to gain or lose by doing the test. They just want their equipment to be respected .

> On the other hand, just like I said. If grass was better then TXG has ALOT to lose. They are a business. Not saying that they aren’t nice guys. But if you had millions on the line, would you let it out that grass is better? Nahhhh of course you wouldn’t .

> Just playing devils advocate . I know there are lots of team TXG’ers here! They are quite entertaining .

I don't think it's millions on the line but I understand your point. However, It's also just way more accessible for the average guy to get fit off a mat because that's much more common. I don't know of a single place around me thats a public facility that offers real grass fitting. Heck, I just finally found a coach in my area that teaches out of a facility that uses real grass...but you can only use it when it hasn't rained, etc.

Basically my point is, even if real grass was "better" universally, it's still not even highly accessible for most people I'd imagine. Maybe it's just my area but for me at least... Tour Spec and Club Champion all seem to do fittings inside off a mat as the standard.

BB28403 · November 13, 2019

> @Z1ggy16 said:

> > @BB28403 said:

> > > @Z1ggy16 said:

> > > > @BB28403 said:

> > > > > @"Howard Jones" said:

> > > > > TXG did a similar test, but with hardly no difference, and that tells us that both the mat itself and the turf we compare it to will always vary

> > > > > Their numbers was about 0,5 higher launch from the mat, and a spin level that was only 70 rpms in difference

> > > > >

> > > > > If you now move to the typical sim forums, you will again see different numbers.....

> > > > >

> > > > > So the club fitter better know how HIS mat works....i used 1* on launch and 800 rpms as "average" or expected difference.

> > > > >

> > > >

> > > > But doesn’t TXG do ALL their fittings on Mats. So you kind of have to wonder, what’s their motivation?

> > > > If they said “oh crap, grass is better than mats!” Then all of their studios would have to be moved outside.... Just saying

> > >

> > > Ian doesn't seem like the kind of guy who would purposely lie and deceive viewers. I've been to TXG and everybody there was super nice and in general, they all seemed like outstanding people. And I feel like it's not a deal of one is "better" than another because as Howard said, there is no single factor or way to convert between the two. For Matt, the grass there vs the mat they used with him, made no big differences.

> > >

> > > @"Howard Jones" would you say perhaps it makes a larger difference for players who tend to hit a little more down on the ball, or play on softer turf? If you're pretty shallow and/or hit off firmer turf... you have less ground interaction overall, no?

> >

> > But Trackman has nothing to gain or lose by doing the test. They just want their equipment to be respected .

> > On the other hand, just like I said. If grass was better then TXG has ALOT to lose. They are a business. Not saying that they aren’t nice guys. But if you had millions on the line, would you let it out that grass is better? Nahhhh of course you wouldn’t .

> > Just playing devils advocate . I know there are lots of team TXG’ers here! They are quite entertaining .

>

> I don't think it's millions on the line but I understand your point. However, It's also just way more accessible for the average guy to get fit off a mat because that's much more common. I don't know of a single place around me thats a public facility that offers real grass fitting. Heck, I just finally found a coach in my area that teaches out of a facility that uses real grass...but you can only use it when it hasn't rained, etc.

>

> Basically my point is, even if real grass was "better" universally, it's still not even highly accessible for most people I'd imagine. Maybe it's just my area but for me at least... Tour Spec and Club Champion all seem to do fittings inside off a mat as the standard.

Yep, that’s the new reality. I don’t mind mats, I just hope I never get mat elbow! ?

Howard_Jones · November 13, 2019

> @Z1ggy16 said:

> > @BB28403 said:

> > > @"Howard Jones" said:

> > > TXG did a similar test, but with hardly no difference, and that tells us that both the mat itself and the turf we compare it to will always vary

> > > Their numbers was about 0,5 higher launch from the mat, and a spin level that was only 70 rpms in difference

> > >

> > > If you now move to the typical sim forums, you will again see different numbers.....

> > >

> > > So the club fitter better know how HIS mat works....i used 1* on launch and 800 rpms as "average" or expected difference.

> > >

> >

> > But doesn’t TXG do ALL their fittings on Mats. So you kind of have to wonder, what’s their motivation?

> > If they said “oh crap, grass is better than mats!” Then all of their studios would have to be moved outside.... Just saying

>

> Ian doesn't seem like the kind of guy who would purposely lie and deceive viewers. I've been to TXG and everybody there was super nice and in general, they all seemed like outstanding people. And I feel like it's not a deal of one is "better" than another because as Howard said, there is no single factor or way to convert between the two. For Matt, the grass there vs the mat they used with him, made no big differences.

>

> @"Howard Jones" would you say perhaps it makes a larger difference for players who tend to hit a little more down on the ball, or play on softer turf? If you're pretty shallow and/or hit off firmer turf... you have less ground interaction overall, no?

Just like you described it, more shallow, less interaction with the surface the ball lies on.

Howard_Jones · November 13, 2019

> @shot-savior said:

> Beyond spin and launch discrepancies, how does one expect to evaluate how an iron's sole will interact with real turf when hitting off a mat? One must really be outdoors, in condition, to properly evaluate a club's performance. I've got to see that ball fly.

>

If the club fitter knows how different sole properties work, that should not a a big issue.

The leading edge is the first to look at, especial on irons since most irons has low static bounce.

If the player is very steep (digger), we want a leading edge thats almost flat heel to toe, and with a large ratio face to sole (not a sharp line seen from the side of the club head)

A large camber (deep curve heel to toe, lowest on the middle) and a sharp edge face to sole is a "agriculture tool" in the hands of a digger, so that club head will dig way more than it should.

The same goes for wedges, look at the leading edge, since that will be first contact point for a digger style swing.

Howard_Jones · November 13, 2019

im adding a chart where ive used PGA and LPGA average numbers from Trackman, and added a few numbers we dont get to see.

Its about all this "rules of thumbs" where some of them is good, other quite misleading. What i want you to look at here is SPIN PROGRESSION from one iron to the next.

We often use the rule of thumb "iron number x 1000 = spin" but you will get to see that we should forget it. The average Loft progression is 4* between irons, so using that rule of thumb we might get to think that 1* loft is 250 Rpms as average, but thats very far from the truth.

LPGA has a average of 600 Rpm club to club and 150 rpm for each degree of loft

PGA has a average of 668 Rpm club to club or 169 rpm for each degree of loft.

Loft to launch is still good as rule of thumb by "loft / 2" = launch

if we tweak lofts 2* strong or weak, what we really can expect is 1* as difference to launch, and 300-400 Rpm change on spin for IRONS, but varieties will always be present just like we can see on this chart, so we really dont have any "fixed factors" for change of spin vs loft, while for launch angle the numbers seems to have less varieties. The average numbers in the bottom of the chart is IRONS only, the others is left out.

And those who wonder what this numbers is, its the relations between the actual club vs driver on that parameter.(gear ratio)

I made a own tread about that "Strange relations PW vs Driver" where we saw that PW carry x 2 = driver Carry for "most" players, just like we see it here

LPGA has a factor of 2.04 and PGA 2.02

BB28403 · November 13, 2019

Are those current? Seems like everyone is 290+ these days on PGA tour.

Howard_Jones · November 13, 2019

> @BB28403 said:

> Are those current? Seems like everyone is 290+ these days on PGA tour.

Its the same numbers that has been around for maybe 6-8 years from Trackman, and its still those that comes up when you search for Trackman PGA average

https://blog.trackmangolf.com/2017-pga-lpga-tour-avg/