SkyTrak Reproducible Misreads Making TGC 2019 Society Tours Unplayable?

[hankydysplasia]

Let me start by saying I have a lot of fun with the SkyTrak - using it daily since Christmas. I enjoy playing with family or the kids. However, I having a hard time believing it can be functional for competitive play.

I know about GungHoGolf's tips. The unit is 0 degrees level in both axes. It is on a flat surface off the mat. My ball is placed appropriately from the laser with drivers back and wedges up. I have a new ball every couple rounds with the logo facing the sensor. Alignment works great and is accurate. I have TGC settings optimized with straight putt, no boosts. When I hit shots in or out of doors, I know where the ball is going within a 5 yard radius in distance and direction 90% of the time. I trust the device on the other 10%. I don't know my swing speed, but my driver ball speed is up to 165 on a good drive. I have a natural draw, and my misses are big hooks or weak push blocks that go shorter. My peak IRL handicap was about a +3 in 2005.

The reproducible problem is with my mid irons. I first noticed it on the Torrey Pines tournament, the 8th hole my 7 iron went 235 yards and they informed me from data on the Discord that it was a misread on the backspin. Unfortunately, at Pebble Beach this week, this happened more 7 irons than not as 3 of the 4 par 3's were 7i distance for me. (FWIW, the 7i is a newish club and clean.) Here is #17 in the first round, which was the epitome of 7i for me that was about 5 feet from intended target:

BS

HA

LA

SA

SS

BS

CA

127.1

1.1

17.5

-3.3

-370

6418

173.48

Here are all the other "correct" 7i's from the round.

128.2

3.9

18.5

-4.9

-581

6781

170.10

128.8

1.3

17.3

-5.7

-627

6288

176.41

129.5

1.3

16.7

-5.7

-626

6278

178.00

Here are a the 7i's that misread.

Hole PAR	1 4	2 5	3 4	4 4	5 3	6 5	7 3	8 4	9 4	10 4	11 4	12 3	13 4	14 5	15 4	16 4	17 3	18 5	72
ROUND 1	4	3	5	4	7	6	3	4	4	3	3	3	4	4	3	4	2	6	72

#3 - second shot from "heavy rough". Out of bounds, cost 2 shots.

131.8

4.9

17.3

7.4

616

4743

195.87

#5 - Shoots of to the right down the cliff, cost at least 2 shots (quad bogey)

131.2

4.3

17.5

-2.5

-216

4962

193.59

#12 - Long slice leaving 40 years back to the hole, saved par.

132.3

1.2

16.0

24.6

1586

3465

207.14

Again, the ball came of the clubhead the same as the "correct" shot. The ball flight is one that I have never once seen of my club in real life and I never have hit that club ~200 yards carry. This is a round where I had 5 birdies and an eagle and was hitting extremely consistently. I shot even par with 5 balls (3 from misreads, 2 due to taking an aggressive line) that had to be rehit. I'm confident that the ball flight was not how the ball was struck in each of these cases.

The second round these were my 7i's:
#12 - Deja vu from round 1. Same spot. Not as lucky and got bogey.

130.3

1.2

16.1

7.4

567

4368

195.18

#17 - Birdied first round, put same swing second round and went 30 yards past.

135.8

0.0

16.1

2.5

218

4995

202.01

And here are 2 driver misreads for good measure
Baseline "normal" drive -

162.5

1.9

11.9

-1.6

-89

3193

270.88

#6 - went into the water with 314y carry - cost 2 shots

176.9

4.9

12.8

3.1

112

2080

314.04

#9 - went 340y in game in fairway on flat but I didn't capitalize on it.

182.1

0.0

11.4

1.6

81

2915

311.51

It is not physically possible for me to hit the ball that hard.

All-in-all, with Guest (probably rightfully) shutting off rewinds, I don't really have the ability to be competitive. Assuming I don't make a single birdie with those swings, it's 9 shots, or the difference between T19 and 4th. At least 8 misreads in 2 rounds. I know it's just internet points, but part of the fun is competing and instead I finish a round frustrated.

The SkyTrak seems to be reading too much ball speed and not enough spin. It also seems to be converting backspin to sidespin. The users that reviewed the shot data on discord suggested that this was a known high speed swing data problem. I'm looking for any recommendations or options. Since this is reproducible, I would think that it could be fixed.

[hankydysplasia]

I’ll use notation of correct/error numbers for brevity.
On the 6i, the ball speed averages 133.7/133.1. Doesn’t seem to be right at 130. I have a handful of ball speeds right at 130 with the 6i that all read fine. Launch angles are 14.8/15.1 for the 6i and 16.8/16.4 for the 7i with lots of overlap with ranges and no patterns. Standard deviation is only 1.0/1.3° according to excel.

Is it possible that the side rotation of the ball eliminates the logo from view or is that no enough side spin?

Back on your idea of ball speed being me and not a misread - I can’t be as sure about this as about the spin being wrong. The 7i correct reads have the smallest standard deviation of my whole bag and the gap between the 6i and 7i is the longest. That’s actually supportive that speeds are correct and the spin is wrong. I would expect to see larger SD on 7i and less of a gap.

Edit:
Visual representation of “correct” shots. X axis is side spin average, y axis is distance, bubble size is ball speed standard deviation. 6i (red) and 7i (yellow) notably smaller with distance gap.

[Morini]

Interesting, it is as if the 6 iron ball speed SD is suspiciously small. It's like only certain values are allowed. Maybe check to see if there is a skewed distribution with a short left tail. And 7 iron ball speed cuts off at 129 for correct readings. Twilight zone.

Ball speed definitely has something to do with this. Not sure how side spin fits it either. Might be easier to see patterns if you switch to spin axis rather than side spin. In either case, even with 1400 side spin, the ball only makes one tenth of a rotation in the y direction (camera perspective) between images, so should be a non-factor.

[Morini]

Actually one tenth of a rotation is 36 degrees. Since effective view of the ball is obviously 180 or less, it is small but could make a difference.

[Morini]

I just came across another user who has the opposite 7 iron problem. Normally 5500 rpm, but occasionally 10K+ for 7 iron. And only in TGC2019.

[hankydysplasia]

Very interesting. Thanks for your continued attention to this. I was just playing Austin Country Club in the ProTee yesterday and had a beautiful drive and a nice 188 downhill to the pin on a difficult green. Put a great swing on it that I thought could possibly make birdie. This is the data that rocketed out -

Austin Country Club (L)

I7

188.00

Fairway

130.9

1.1

17.4

-13.1

-802

3450

207.09

The thing went like 225 yards. I made triple bogey.
It's just so frustratingly.

The interesting thing if it's really is 7i it's probably launch angle related which I can't explain. Seems like it would happen to more people then.
I wish they took into account the TGC club data in the application. They could see the 7i, 126 speed and get the spin rate much better. That is assuming there's not a camera issue.

[Morini]

So does it happen only in TGC2019? Or in range as well?

Again, it is the 130 mph ball speed. It might be that it is the horizontal ball speed vector that we should look at. And that depends on launch angle. The problem is definitely also launch angle related. The horizontal ball speed on the shot you posted was124 mph.

If you think about it, this horizontal velocity is quite rare. Only very fast players will get it with 7 iron. Others will get it with 6 iron. But as you go to woods, with higher speeds and lower launch angle, most are over it. And woods have low spin anyways.

At 124 mph, The ball travels 2.27 inches between images. I have no clue how the imagers work, but I imagine that the strobes are fired so that the ball is captured symmetrically between two imagers. As I have speculated before, there might be some type of blind spot at around this distance.

I just looked at the TXG video again. Similar horizontal ball speeds on their bad reads. 124 on one, 126 on another.

[SomaPLR]

Mine is happening on the range feature as I don’t use ST to play golf, so it's the actual software and this has been a pretty recent for me as I just dusted mine off after a couple month hiatus - running into a lot of the same issues. I carry a 7i about 180 on Trackman outside. I’m getting some pretty wild low spin readings lately...

This is pretty wild we are having the exact same issue. Anytime I hit over 130mph ball speed with a 7iron, the machine goes haywire. If I keep it at 127-128 it seems fine. I just started a thread about this I thought it was the lighting in my garage...guess it's not. Looks like we broke the Matrix.

[hankydysplasia]

This is pretty wild we are having the exact same issue. Anytime I hit over 130mph ball speed with a 7iron, the machine goes haywire. If I keep it at 127-128 it seems fine. I just started a thread about this I thought it was the lighting in my garage...guess it's not. Looks like we broke the Matrix.

I will post the response from SkyGolf when I get one. I had a very good phone call and email exchange after request for data. I provided them with hundreds of shots. With you, others on Discord, and TXG video review collaborating, I’m 100% sure this is a fixed bug and not due to setup or individual unit.

After first line said they would be sending to engineering team it has been radio silence for 2 weeks. I sent a bump last week.

[Morini]

Yes, I have brought this up repeatedly, and you could be your last dollar that Skytrak is trying to figure out what happened on the disastrous TXG review. If I had seen that before buying my unit, I would have passed. Bad luck that TXG testers ball speed fell right in this exact window of 128 to 130, as it made the Skytrak look much worse than it really is. It is a meme now that skytrak can't handle fast swing speeds.

Clearly Skytrak is choosing to remain silent on this. Which is fine by me, as long as somebody is on it. As I posted in the other thread, try rolling back ST range to pre-high ball speed fix and see if makes any difference.

[SomaPLR]

I watched that review. Bunch of comments said Matty has the SkyTrack too high off the mat, and mine's sit's flush with the case. I don't think that's the issue. Look, I still think ST is a fine product. I was hitting 3 woods today off the deck and getting great numbers. There is something with that particular launch angle and speed that's just not connecting. It's shame I was actually going to buy TPC but I think it would drive me nuts like Hanksy. Alll I have to do on the driving range feature is move on.

[Morini]

Yes, it is tied to very specific launch window. At the time of the review, I also felt that they were doing something wrong ... because spin has always been accurate. I think this is recent, and as I suggested, try to roll back to older ST range. You could always avoid this launch window for now.

[SkyTrak_Seth]

Hey guys, thanks for your diligence on this. I'm more than happy to investigate this further and run it up the chain. Like I mentioned earlier, these are my numbers and I've never noticed anything like this, but if there is anything that needs to be addressed, be assured we will get it taken care of.

[Morini]

PGA Tour ++ ball speeds. Impressive, Seth.

[SkyTrak_Seth]

I didn't say they always go straight...

[hankydysplasia]

Thanks for stepping in, Seth. I noted your comment from the other thread -

1) Play around with the ball position, try moving to the right of the laser dot (away from the target) about 1 inch. 2) Always make sure to line up an identifiable mark (logo works, but ideally a line) to the SkyTrak prior to hitting.

I have modified my hitting environment in every way that has ever been suggested on this forum in an attempt to reduce the likelihood of misread.

Also, as far as addressing it, I was told by Rodgeric at SkyTrak that I was to work through him. I provided him with over 840 shots worth of data. I last heard from him on March 29, and have emailed multiple times since with no response. I started this thread on 2/13. I remain interested in working with you to fix the problem.

[hankydysplasia]

SkyTrak_Seth It has now been 3 months since SkyTrak has responded to my emails about this issue. Their last communication was:

"Thank you Mr. Fitch for the details that you have provided, this has been sent to our development team for further review. I will notify you soon as I get a response from that team. Thank you in advance for being patient."

I would be willing to beta test software or have calls with the development team to fix this problem.

[Morini]

Any news or updates about this. I continue to see anecdotes where people with high 7 iron ball speed have low spin. Also a few the opposite. Slow driver with doubled or quadrupled spin. Maybe some type of disambiguation process that gets it wrong for specific ball speeds and trajectories.

[hankydysplasia]

Unfortunately, it does appear that the advice I received from ex-SkyTrak users in the discord was correct - don't expect a fix to this. They have not responded.
I haven't been using the SkyTrak as much this summer as I have been trying to get outside instead. I'll be back pulling more data in the fall.

[Morini]

Hi hankysyplasia,

I assume you have not had any updates on this. Just to confirm, these reads happen in both TGC2019 and in Skytrak range? There are still quite a few skytrak users complaining about this, and think it is definitely a real thing. TXG pretty well proved it, but they did not do side by side, so not conclusive.

Did you ever try to replicate it with older pre-high ball speed fix version of Skytrak range? I feel that this started happening around the time image engine was updated with the fix. Also, haven't seen anyone using E6 complain about it, which would make sense since E6 does not have the fix.

[Morini]

I now have more examples of golfers with mysteriously HIGH 7 iron spin. Slower ball speed (95 to 110 range), but similar VLA, 20 degrees. Basically spin is doubled, just under 12K. For those swing speeds off mat, about 6K rpm sounds about right.