Mevo+ vs SkyTrak data compilation from a session today

[GungHoGolf]

I really feel like we need to test against a GC2 or GC Quad and get quite a few data points.

I have a SkyTrak which I think is decent for accuracy but not the defining “truth” (I appreciate none are perfect).

My SkyTrak never gives HLA between .1 and 1.8 it either reports zero or 1.8 (negative or positive). I also get a reasonable number of shots that HLA is clearly wrong in a session. They are easy to identify as I have a target towel in the middle of my net that trigonometry tells me if I hit the towel it’s at most 5* HLA in either direction. I’d suspect Mevo+ should win on HLA accuracy.

The spin is tougher to judge. I’ve always given my SkyTrak the benefit of the doubt on total spin as I mostly hit irons in my garage with it due to ceiling height. That said when I hit driver occasionally the spin always reads way higher than I’d expect based on other data sources. I see a lot of 3K and 4K spin values which are suspect based on my swing numbers and course distances.

I wonder how the Mevo+ is doing spin if it’s not read properly. I’m guessing there is no italics or flag on calculated vs measured spin. I’d be really curious outdoors what the driver spins look like on both devices (in a setup where sun light not impacting SkyTrak). I wonder if Mevo is defaulting to its club data and it won’t have strike location for fear effect etc.

I always feel the curvature is way too high on my SkyTrak relative to outside. Whether that’s measurement or algorithm I don’t know.

Mevo+ is likely having trouble with driver spin because in 9' of ball flight with a 140mph ball speed and 2,500 spin, the ball only rotates about 1.5 revolutions before hitting the screen. If this is the case, higher speed players will see even more discrepancies.

SkyTrak measures HLA to the nearest 10th of a degree, but the range interface rounds anything under 1 to 0, and anything over 1 to 2. So you never see an angle of 1 when using the range. I've complained about this, but it has fallen on deaf ears. Their explanation is that HLA is accurate to only +-2 deg, but why you wouldn't still round a 1.1 instead of to a 2 makes no sense.

The data is stored in the SkyTrak shots db with full precision. Here is a screenshot from my Advanced Analytics - you can see plenty of HLA shots between 2 and 0: https://www.dropbox.com/s/jcankx9bfd...18.21.png?dl=0

Learn more about Advanced Analytics at https://gunghogolf.com/blog/Advanced...cs-for-SkyTrak

[Gresh12]

I went in to my DB file once and still never saw anything between -1.8 to +1.8 except exactly 0.

[Woosie]

Mevo+ is likely having trouble with driver spin because in 9' of ball flight with a 140mph ball speed and 2,500 spin, the ball only rotates about 1.5 revolutions before hitting the screen.

My maths says over 100 revolutions:

9 / (140 * 5280) * 3600 * 2500

[JackedUpSwing]

Yea I think you're 3600 should be a 60.

So 1.82 rotations.

1.28 rotations with ball speed of 160 and 2k spin.

[pwade3]

So if I play at 13’ then it would be 2.63 which would give it a longer time frame to get a read on the ball. (In theory)

[Woosie]

D'oh! rpm = revolutions per minute 🙄🤭

Hardly surprising that indoor spin numbers are inaccurate.

[Bubba22]

My concern is spin axis. Gung correct me if I am wrong but there are 14 out of 38 shots that show a ball with the opposite spin axis ie. opposite shot shape. Am I reading that right?

[Bubba22]

That's because your too a golfer Gung. We need you to show us some comparison shots with crazy hooks and slices! Lol!

[GungHoGolf]

I'll make sure to hit some crazy hooks and draws when doing the next round of tests; hoping to round up one of my high-speed buddies to be the test subject.

[Bubba22]

Cool. Looking forward to your reviews.

[Dax]

Agree the 3600 should be 60, the ball is spinning at 2500 revs per minute not per second.

[wbond]

That is what i noticed as well. It would be different if they were off but the same direction. Being off and opposite is not good.

My concern is spin axis. Gung correct me if I am wrong but there are 14 out of 38 shots that show a ball with the opposite spin axis ie. opposite shot shape. Am I reading that right?

[Celeras]

I don't think that's a fair assumption that it will flop. Even Trackman is all over the place with spin axis inside. It's a flaw of the technology (radar), not the specific product.

[trumb1mj]

Doesn't spin axis determine the shape of the shot? I had no idea that this was a struggle for radar in a limited flight setting.

[GungHoGolf]

Outdoors, radar tracks the actual ball flight curvature to measure spin axis. Indoors, there is no curve in the first 9-10' of flight, so it has to pick up differences in the reflected radar signal for a non-horizontal spin axis – considerably more demanding.

[Tom919]

Great video from another user showing spin rates are similar but carry distances are off vs. HD golf. Pretty consistent 10-15 yards difference.

https://youtu.be/XxaLw1FUbUU

[Bubba22]

On 1 shot the Meavo sidespin was 1245 and backspin 2264 and HD spin axis was 1.2 degrees which are not close. Other data seemed close which is promising.

[pwade3]

I went back and had a look at that. I think it was 1.48 which is still not close but which unit was wrong?

[GungHoGolf]

If you have one clock, you know what time it is. If you have two clocks, you don't.

[a98cr125]

Here is a quick video I did for showing shot shapes. Fade, Draw, Hook, Slice etc.

[trumb1mj]

I will say, SkyTrak miscaptures spin axis/reversed shot shape from time to time. I have a handful of those per 100 shots.

[wbond]

Can you hit some putts that stop just short of your screen and some chips that land just short of the screen? I think you mentioned that you are 10', so this will be a great indicator if the Mevo+ is truly capable of sim play with TGC when it becomes available.

Here is a quick video I did for showing shot shapes. Fade, Draw, Hook, Slice etc.

[a98cr125]

Let me get some free time and I will try to knock it out.

[Dax]

Can you hit some putts that stop just short of your screen and some chips that land just short of the screen? I think you mentioned that you are 10', so this will be a great indicator if the Mevo+ is truly capable of sim play with TGC when it becomes available.

WBond, I thought that someone did a putting video on youtube? I can't recall but thought they were doing 8 to 10 foot putts... Also, the same person that posted the above video also has a short chip video.

[tonybrown32]

I really feel like we need to test against a GC2 or GC Quad and get quite a few data points.

I have a SkyTrak which I think is decent for accuracy but not the defining “truth” (I appreciate none are perfect).

My SkyTrak never gives HLA between .1 and 1.8 it either reports zero or 1.8 (negative or positive). I also get a reasonable number of shots that HLA is clearly wrong in a session. They are easy to identify as I have a target towel in the middle of my net that trigonometry tells me if I hit the towel it’s at most 5* HLA in either direction. I’d suspect Mevo+ should win on HLA accuracy.

The spin is tougher to judge. I’ve always given my SkyTrak the benefit of the doubt on total spin as I mostly hit irons in my garage with it due to ceiling height. That said when I hit driver occasionally the spin always reads way higher than I’d expect based on other data sources. I see a lot of 3K and 4K spin values which are suspect based on my swing numbers and course distances.

I wonder how the Mevo+ is doing spin if it’s not read properly. I’m guessing there is no italics or flag on calculated vs measured spin. I’d be really curious outdoors what the driver spins look like on both devices (in a setup where sun light not impacting SkyTrak). I wonder if Mevo is defaulting to its club data and it won’t have strike location for fear effect etc.

I always feel the curvature is way too high on my SkyTrak relative to outside. Whether that’s measurement or algorithm I don’t know.

I have the same sentiments here. This has also been my experience with the Skytrak as well... not saying it in a bad way at all. Skytrak consistently exaggerates left spin axis compared to what I see outdoors in play or on the range. Skytrak consistently provides me lower iron and driver spin numbers than what I see on GCQuad or Flightscope X3 sessions I have had as well. Horizontal launch is the parameter on Skytrak i'm least comfortable with. Like others have mentioned, I can validate when it's wrong with my own eyes, like when a ball clearly strikes my screen right of center line, but Skytrak shows the ball starting left... I disregard those shots as misreads... they don't ocurr every shot, but I would say easily 10-15% of my shots read an incorrect HLA on Skytrak at least in my sessions. Vertical launch is also suspicious to me sometimes, but I really don't use that parameter much anyway.. Other parameters on Skytrack seem pretty spot on from what I see on course.

Not drastic difference, but identifiable and consistent differences. That's fine with me honestly, as long as the differences are consistent.. each manufacturer (SkyTrak, Flightscope, Trackman etc) are going to have different flight algorithms and different ways they derive the data parameters... indoors all of them are only tracking or measuring limited flight, and calculating the end results via algorithms... each slightly different. Expect them all to show differences on the same shots.

[wbond]

I will try to find those. The one i saw from the poster, all of his chips carried into the screen with some force, i was guessing more than 8 yds of carry or so. I'll check again. Did the putts get read at 8'?

WBond, I thought that someone did a putting video on youtube? I can't recall but thought they were doing 8 to 10 foot putts... Also, the same person that posted the above video also has a short chip video.

[Dax]

He had them set for 10’2” putts.

[wbond]

Do you have a link to this video, I couldn’t find one with 10’ putts

[GungHoGolf]

wbond this is mine: https://www.youtube.com/watch?v=Y8ezF524U0s

[Brutaly]

GungHoGolf can you set it up 6 feet behind the ball (the closest i and i think many with me would be comfortable with) and 8 feet to the screen. and do the exact same test, iron 7 only would be good enough. That way we would at least have a hunch regarding how it affects reliability. I know from when i had the Xi+ i could use really weird setups and still have acceptable data for sim play. It wasnt good enough for fitting though,