SkyTrak Distances vs Real Life

[Morini]

On launch monitors, carry is all that matters (assuming that landing angle is in an acceptable range). Roll out is very dependent on course conditions.

Are you talking about ST range or sim rollout?

[BogeyMonster]

Both. TGC2019 and the SkyTrak PC App.

I just don't understand where the app and TGC are getting this notion that a long iron rolls out ~25 yards. I don't think I've ever seen that happen in reality.

[AndyF]

Try hitting your mid irons off a small tee to remove the effect of the mat completely and see if the numbers change.

Also post up some numbers that you're getting in terms of launch angle, ball speed and spin numbers as that will help identify the issue

Andy

[abenjami]

I took my Skytrak to the range today to see how accurate it is. It was WAY off on carry distances.

How do I know this? Because I also took my range finder with me and was using a CGQuad launch monitor provided by my driving range. I pegged a target 70 yards away at the range using my range finder, then hit a few balls until I hit one that literally landed right next to the target. My Skytrack carry distance was 10 yards short.

I tried adjusting the altitude setting on the Skytrak. I started at 500 feet above sea level, as that is close to the actual altitude where I'm at. I bumped it up 500 feet to 1000, then hit a few more balls until I hit one that landed right on the target again. I did this several times until my altitude was at 2000 feet and the carry distance on the Skytrak matched balls I hit that landed on target.

I thought this fixed the issue but I was wrong. Next, I used the range finder to scope out a target at 135 yards. Hit some more balls and Skytrak was short again. I repeated the above process and finally at 3500 feet it was accurate at 135 yards. But then I left it at 3500 feet and went back to hitting to the 70 yard target, and as would be expected the Skytrak was now long on the carry distance.

Does anyone know how to calibrate this thing? I've owned it for about 2 months and thought it was pretty off the entire time.

[Gazpacho]

I didn’t think Skytrak works outdoors. My Skytrak is unreal accurate and Skytrak has been shown to be equally as accurate as trackman

[Morini]

Outdoor is the way to go if:

• There is no wind
• ST shielded from direct sun.
• You use premium balls, not range balls
• Have an exact way to measure carry (spotter and laser)

[abenjami]

Outdoor is the way to go if:

• There is no wind
• ST shielded from direct sun.
• You use premium balls, not range balls
• Have an exact way to measure carry (spotter and laser)

When I took it outdoors this weekend, there was no wind and it was in the shade. I also had an exact way to measure carry using my range finder and targets on the range.

I was using range balls, but why would that matter? I hit a range ball that carried 135 yards using a range finder/target and the Skytrak reading was about 12 yards short.

[Morini]

From personal experience, range balls were all over the place when I tried to verify at the range. Tried it in a field with spotter and premium ball, +- 2 most of the time, with the odd read much worse. Not exactly sure why, but that is what it was.

i did find short pitches long, long drives short, and most in between very slightly short, so juiced with elevation, just as you did.

[Thebogeyman]

Any workaround on this BogeyMonster? I am having a similar issue - the PW to 8 are as expected, but I get massive flyers with my 6 and 7 iron. Some seem correct but some travel a good 10% further than I can possibly hit

[trumb1mj]

Depending on your mat, carry can be exaggerated by the lack of spin. My real feel kills spin.

[BogeyMonster]

Any workaround on this BogeyMonster? I am having a similar issue - the PW to 8 are as expected, but I get massive flyers with my 6 and 7 iron. Some seem correct but some travel a good 10% further than I can possibly hit

I had to stop using the SkyTrak software and now I just use TGC2019. In the settings file for TGC2019 I set my Iron Boost to -6 and left the Wedge Boost at 0. If I'm hitting a 4i-7i the -6 iron boost seems to give me the correct distance. If I'm hitting my 8i or 9i I tell the game I am hitting a wedge so the -6 boost is not applied. A little clunky, but it's the only thing that has worked.

[Morini]

I am still interested in figuring out the cause of this. Would you mind sharing the ball data for say 6 iron. For reference, there is 5 mph ball speed difference between irons (exception being 6 to 7 which is 7 mph) for PGA tour. You are pretty close to PGA tour numbers, so should be similar. For 5 to 9 iron, there is 2 degrees per club increase in launch angle. There is 800-900 increase in spin per club. Finally, landing angle goes from 49 degrees for 5 iron to 51 degrees for 9 iron.

Since I doubt that the ball flight and roll out model is the culprit, there must be something whacked in your actual ball data. Most likely club mat interaction for selective lofts. Checking the "gapping" in terms of ball speed, launch angle, spin and landing angle (calculated obviously) may shed some light on what is going on.

[FURY]

Hi All!

I am contemplating the purchase of a ball, and maybe club tracking device. Have been reading about Skytrak, Gc2 amd Quad. Has anyone, who has had the above stated variance with the Skytrak compared with the Foresight or even Trackman offerings? If so, please comment/share results. It probably does not come up often, but my garage sapce will not allow driver to be used with impunity, as it "can" reach the ceiling on followthrough, so outdoor range protability of device is something I would like to have.

Thank you very much

FURY

[Morini]

My guess is that in this particular situation, the ST is reading the ball data correctly. Thus a GC 2/trackman would have the exact same data.

[MisterA]

For me, my carry and total numbers are all over the place. Below are some numbers of a recent practice session I did. I was hitting outside in a net, not in direct sunlight, using Bridgestone B RXS balls. I was hitting my 7 iron, on course I hit about 170m or 186yards. During lessons on the driving range I see that spin is in the 6000's (using trackman), and I hit my normal distance.

What I notice in the numbers below: some shots come up short to my normal carry numbers, but most of the time my spin is above normal (8000 and above). On other occasions I supposedly hit +220yards with spin being only 2000-3000rpm. I understand that spin can explain the exagerated (both ways) carry numbers, the problem is that I don't havy any means to recalculate with a degree of certainty my 'true numbers'. In another thread I read that minimal side spin difference can already have a substantial impact on draw/fade numbers. So I wonder if my offline numbers are to be trusted either.

It's also holding me off to buy TGC or something like that, it's no fun playing when your carry numbers are all over the place.

I tried using different balls with extra markings on them for example, also Chromesoft Truvis balls (blue ones). But the number I get keep being erratic.

BALL	LAUNCH	BACK	SIDE	CARRY	TOTAL	CLUB
MPH	DEG	RPM	RPM	yards	yards	MPH
124	19	8106	-1284	168.5	176.1	94
123	16.2	2258	-1192	184.9	209.0	79
114	18.5	4921	494	165.2	178.3	79
128	18	6575	376	180.5	190.4	93
119	18.6	8763	-1006	159.7	166.3	94
125	18.2	5591	886	180.5	192.5	88
125	18.5	11813	507	149.9	154.3	99
126	23	5264	-150	186.0	198.0	88
127	19.5	8131	-1051	172.9	180.5	96
126	16.6	4692	336	189.3	203.5	86
127	17.4	5792	1612	180.5	192.5	90
129	18.3	6547	563	182.7	192.5	94
124	14.6	6372	-1010	175.0	184.9	91
121	12.7	2786	-818	176.1	198.0	78
134	16.9	4892	-140	204.6	218.8	92
131	17.5	2275	-704	215.5	240.7	84
127	22.1	5680	-81	183.8	195.8	90
132	17.9	3743	1336	202.4	219.9	88
124	20.7	8383	-841	167.4	175.0	95
122	17.7	7663	-438	169.6	176.1	95
118	17.4	3720	922	176.1	193.6	79
125	15.6	6537	374	176.1	186.0	92
123	19.1	6979	100	169.6	177.2	92
125	18.9	6973	499	171.8	180.5	93
132	16.7	5357	77	198.0	210.0	92
131	18.1	4260	-1120	199.1	214.4	88
120	17.1	6282	-1367	167.4	177.2	88
123	23.4	7978	-916	164.1	171.8	96
125	11.4	5495	-2801	168.5	182.7	88
132	20.5	4110	2170	195.8	213.3	89
130	21.8	5208	598	193.6	206.8	90
132	18.4	3974	341	205.7	222.1	88
128	18.9	8356	-1080	175.0	182.7	98
130	20.4	4834	207	196.9	211.1	89
129	19.2	3206	-229	207.9	227.6	84
120	16.1	5679	-149	159.7	173.9	85

[kokoskorpen]

I’m a total noob when it comes to ST, but can the mat you’re hitting from impact the spin numbers? I’m have the same issue, sometimes 10000 spin on a 7-iron on shots that feels good but are very short on ST. I’m hitting from a carpet in my livingroom.

[GungHoGolf]

Your launch angles are all over the place, too - from 11 to 23 - leading me to think your face contact and perhaps AoA has a lot of variation, which could impact spin numbers. SkyTrak rarely misses getting the vertical launch angle correct, as that's a very easy thing to measure given two photos of a ball. Spin is a tougher thing to measure for SkyTrak - what helps the most is to always place the logo of the ball towards the cameras, and use white or otherwise solid-colored balls. I know some guys have success with Truvis, but I can't help but think all those hexagon blotches on the ball might confuse the computer vision algorithms when it's trying to pick out landmarks on the ball to measure the degrees of rotation.

To better track your trends with your shot data, you might give our Advanced Analytics a try. It will show you your standard deviations for all data, and is the best way to look at trends over a period of time. Find the demo at https://gunghogolf.com/ron/analytics, and you can sign up during this beta period at https://gunghogolf.com/signup with invite code 2019-021.

[OC_Mike]

I'm having the same problem with my Skytrak currently. It's always been spot on with my distances and now it's reading massively long. I get the same results and have tried: CCE mat, Fiberbuilt insert, garage lights on & off, changing balls, dark tarp behind me blocking out any reflections, raising and lowering the skytrak. In real life I hit my 7 iron 175, maybe 180 if I want to go after it. I'm frequently getting 200+ carry on the skytrak with ridiculously low spin numbers. Ball speed seems high for that swing speed? Here's a picture of a shot from last night. Any suggestions? I think I may need to send it in for repairs? Help!

[GungHoGolf]

Ball logo towards cameras? This is so weird, with several people reporting sudden changes of distance and spin readings, both long and short. Would expect something like this with a software update, but there has been none (that we know of).

Don't pay attention much to club speed. Has your ball speed changed, or just lower spin numbers?

[FaultyClubs]

Distances match what would be expected from the measured ball parameters so flight algorithm seems fine.

Ball speed of 131 mph on a 7 iron isn't believable though (lpga is 104mph and pga is 120mph) so something doesn't add up. What are your normal values for 7 iron?

[BogeyMonster]

I am still interested in figuring out the cause of this. Would you mind sharing the ball data for say 6 iron.

Here is some data from a few 6 iron shots from my CCE mat (no tee):

6I

CLUB	BALL	BACK	SIDE	CARRY	TOTAL	LAUNCH
MPH	MPH	RPM	RPM	YARDS	YARDS	ANGLE
84	122	5985	418	175	185	21
85	124	5117	-583	183	197	20
83	120	5200	-299	176	190	20
84	123	6247	174	174	186	18

For reference, in real life my 6 iron typically has a total distance of 170-175.

[Morini]

Will double check with flightscope optimizer in a bit, but that seems to launch high and spin a bit low. That is very common with mats as there is not enough friction, so the ball slides up the face. Perhaps your swing and this particular mat combine in these particular lofts. The only way to know for sure is to take your mat to the range.

[GungHoGolf]

Mats vs grass with 7-iron: https://blog.trackmangolf.com/mats-v...ts-difference/ - 2.7 deg higher launch and 25% less spin on mats compared to grass.

In my opinion, this difference is due to the club moving through the ball at a shallower AoA, either from the player making a shallower pass on mats subconsciously to avoid hurting themselves, or the club physically being prevented from continuing down through impact, so it sort of slides/skips through more level through impact. One would think that mats accommodating "virtual" divots better (TrueStrike, DivotAction, Fiberbuilt, Magstrike) should minimize this effect.

[Morini]

Thanks for posting that GungHoGolf. The combination of higher launch and lower spin seems to give a flyer flight with 8 yards more carry, which would mostly explain Bogey Monsters extra carry. If this is the cause, you would have the same results from GC2, Quad, TM, FS and real life.

I wonder if it is possible to develop a "normalization" algorithm that will put the spin & VLA back to what it would be off turf ... in order to equalize sim and real world numbers. Enter your mat model, and some basic swing tendencies, and let the algorithm take it from there.