Distance is inaccurate with the woods

[bennyg211]

Be interesting to know what version of the firmware you are running on your Skytrak, can you confirm? I doubt its different from the masses, but you never know.

[doublebogey]

Took my SkyTrak to the range and again it shows SkyTrak is quite accurate from irons up to my 3 wood. Again harder to tell with driver if off by 10-20 yards without somebody down there marking where the ball lands and rolls to. Overall accurate enough for me.

[hks8888]

Ball ||| VLA ||| HLA ||| Spin |||| SpinAxis ||| Skytrak(Carry) ||| GC2 ||| FTO(Carry) ||| Optimal Flight ||| Trackman
184 ||| 16 ||||||| 9 ||||||||| 2917 ||| 31L |||||||||||||| 306 |||||||||||||||||||||||| N/A |||| 329 ||||||||||||||||| 304
166 ||| 14 ||||||| 0 ||||||||| 2083 ||| 16L |||||||||||||| 279 |||||||||||||||||||||||| N/A |||| 286 ||||||||||||||||| 280.6
148 ||| 18 ||||||| 0 ||||||||| 2024 ||| 0 ||||||||||||||||||| 257 |||||||||||||||||||||||| N/A |||| 254 ||||||||||||||||| 255.7

166 ||| 14 ||||||| 5 ||||||||| 2324 ||| 1L ||||||||||||||||| N/A |||||||||||||||||||||||| 295 |||| 288 ||||||||||||||||| 286.2
168 ||| 13 ||||||| 2 ||||||||| 2249 ||| 2L ||||||||||||||||| N/A |||||||||||||||||||||||| 299 |||| 289 ||||||||||||||||| 287.4
161 ||| 17 ||||||| 5 ||||||||| 2240 ||| 2L ||||||||||||||||| N/A |||||||||||||||||||||||| 290 |||| 283 ||||||||||||||||| 281.4
159 ||| 17 ||||||| 4 ||||||||| 2150 ||| 6L ||||||||||||||||| N/A |||||||||||||||||||||||| 286 |||| 278 ||||||||||||||||| 276.9

FYI: Justin Rose Trackman Data (outdoor) https://www.youtube.com/watch?v=43u0rlZ3s_E
165.7 ||| 16.4 ||| 3.1 ||||| 2361 ||| 1.5R |||||||||| N/A |||||||||||||||||||||| N/A |||| 297 ||||||||||||||||||| 289.4 ||||||||||||||||||||| 294
173.7 ||| 11.9 ||| -1.1||||| 3004 ||| 1.7R |||||||||| N/A |||||||||||||||||||||| N/A |||| 300.7 |||||||||||||||| 296.9 ||||||||||||||||||||| 296

Keep in mind that a comparison to Trackman here is not fair. It is not Apple to Apple comparison because there is no information on altitude, temperature and wind. Being said that, OF and Trackman is really close to each other on driver shots. (I just randomly picked two shots out of 10 shown on the youtube video) and FTO is also close. Statistically, it means nothing because of a small number of samples, but I just hope that we can get a little better understanding on how to interpret ball launching data.

[Fawley]

Be interesting to know what version of the firmware you are running on your Skytrak, can you confirm? I doubt its different from the masses, but you never know.

I'm not sure, but would be happy to take a look tonight. How do I check?

[TorchRedRob]

Ball ||| VLA ||| HLA ||| Spin |||| SpinAxis ||| Skytrak(Carry) ||| GC2 ||| FTO(Carry) ||| Optimal Flight ||| Trackman
184 ||| 16 ||||||| 9 ||||||||| 2917 ||| 31L |||||||||||||| 306 |||||||||||||||||||||||| N/A |||| 329 ||||||||||||||||| 304
166 ||| 14 ||||||| 0 ||||||||| 2083 ||| 16L |||||||||||||| 279 |||||||||||||||||||||||| N/A |||| 286 ||||||||||||||||| 280.6
148 ||| 18 ||||||| 0 ||||||||| 2024 ||| 0 ||||||||||||||||||| 257 |||||||||||||||||||||||| N/A |||| 254 ||||||||||||||||| 255.7

166 ||| 14 ||||||| 5 ||||||||| 2324 ||| 1L ||||||||||||||||| N/A |||||||||||||||||||||||| 295 |||| 288 ||||||||||||||||| 286.2
168 ||| 13 ||||||| 2 ||||||||| 2249 ||| 2L ||||||||||||||||| N/A |||||||||||||||||||||||| 299 |||| 289 ||||||||||||||||| 287.4
161 ||| 17 ||||||| 5 ||||||||| 2240 ||| 2L ||||||||||||||||| N/A |||||||||||||||||||||||| 290 |||| 283 ||||||||||||||||| 281.4
159 ||| 17 ||||||| 4 ||||||||| 2150 ||| 6L ||||||||||||||||| N/A |||||||||||||||||||||||| 286 |||| 278 ||||||||||||||||| 276.9

FYI: Just Rose Trackman Data (outdoor) https://www.youtube.com/watch?v=43u0rlZ3s_E
165.7 ||| 16.4 ||| 3.1 ||||| 2361 ||| 1.5R |||||||||| N/A |||||||||||||||||||||| N/A |||| 297 ||||||||||||||||||| 289.4 ||||||||||||||||||||| 294
173.7 ||| 11.9 ||| -1.1||||| 3004 ||| 1.7R |||||||||| N/A |||||||||||||||||||||| N/A |||| 300.7 |||||||||||||||| 296.9 ||||||||||||||||||||| 296

Keep in mind that a comparison to Trackman here is not fair. It is not Apple to Apple comparison because there is no information on altitude, temperature and wind. Being said that, OF and Trackman is really close to each other on driver shots. (I just randomly picked two shots out of 10 shown on the youtube video) and FTO is also close. Statistically, it means nothing because of a small number of samples, but I just hope that we can get a little better understanding on how to interpret ball launching data.

Thanks for adding those. I agree with you- it's nice to look at actual data to gain a better understanding.

Could you please check one other thing in OF? Could you change my 2nd shot from 16L spin axis to 0 spin axis to see how much impact it has on carry? FTO didn't show much change due to axis variation, but I wonder what OF says about it. Thanks in advance!

[Willymakit]

Just wondering on one more thing before I believe this is a defective unit. When using an iron and when I hit a shot that has center spin and side angle I'm very close to the center line. But when I hit the exact same shot with the woods with center spin and center side spin I'm roughly 7-15 yards offline. Can any confirm this.

[hks8888]

Just wondering on one more thing before I believe this is a defective unit. When using an iron and when I hit a shot that has center spin and side angle I'm very close to the center line. But when I hit the exact same shot with the woods with center spin and center side spin I'm roughly 7-15 yards offline. Can any confirm this.

Well, as far as I know, "center" doesn't mean "0" (zero). It could mean somewhere between 0 to 1 ( or 1.5 which I am not certain about.) for side angle. So, your offline yardages might be reasonable for over 200 yard shots. I wish Seth could confirm about what 'center' means.

[hks8888]

Thanks for adding those. I agree with you- it's nice to look at actual data to gain a better understanding.

Could you please check one other thing in OF? Could you change my 2nd shot from 16L spin axis to 0 spin axis to see how much impact it has on carry? FTO didn't show much change due to axis variation, but I wonder what OF says about it. Thanks in advance!

Ball ||| VLA ||| HLA ||| Spin |||| SpinAxis ||| Skytrak(Carry) ||| GC2 ||| FTO(Carry) ||| Optimal Flight
166 ||| 14 ||||||| 0 ||||||||| 2083 ||| 16L |||||||||||||| 279 |||||||||||||||||||||||| N/A |||| 286 ||||||||||||||||| 280.6
166 ||| 14 ||||||| 0 ||||||||| 2083 ||| 0 |||||||||||||| N/A|||||||||||||||||||||||| N/A |||| 287 ||||||||||||||||| 284.9

[TorchRedRob]

Very interesting. Thanks for doing that.

[mhage]

I think that is where Skytrak has issues. With numbers similar to those, skytrak shows the ball bending way left and the others show it just barely moving left.

yes, more of a glancing blow but not enough to account for significant yardage. For example, If I plug the launch conditions into FTO and change the axis from 16 to 0, carry goes from 286.4 to 287.7, so I'm only losing 1.7 yds... according to FTO, anyway. Similarly, if I change his shot from 1L to 16L, his carry only decreases from 288.2 to 287.0, or only 1.2 yds lost.

So, in the FTO model, spin axis is a small contributor from 0-16 degrees, but I'm curious to see what Optimal Flight says about it.

Also, for what it's worth, it's not way left at 16 degrees. If I had launched it only 2.5R, it would have come back to centerline when it landed.

[Willymakit]

Well, as far as I know, "center" doesn't mean "0" (zero). It could mean somewhere between 0 to 1 ( or 1.5 which I am not certain about.) for side angle. So, your offline yardages might be reasonable for over 200 yard shots. I wish Seth could confirm about what 'center' means.

Can you or somebody verify it by going to the range and hit s center / center shot and see what the distance offline to center line is. With my hybrid I can barely get over 200 yards and it veers left or right offline by 15 yards either way when hit center/center

But I can hit a 4 iron 210 yards center/ center and be 1-3 yards offline.

[hks8888]

I think that is where Skytrak has issues. With numbers similar to those, skytrak shows the ball bending way left and the others show it just barely moving left.

There have been some people who felt (or witnessed) that Skytrak's curvature is excessive. I felt the same way, but nobody present meaningful data until now (I know it would be extremely difficult to measure curvature outdoors.) My interpretation of shots on Skytrak is to reduce 30% of offline yardages. For example, I see 10 yards left off the target as 7 yards left. I am not saying that my way of reading is correct. FTO doesn't give a number for curvature, but its shot simulation seems to give a lot less curvature. I think Optimal Flight sits in between FTO and Skytrak regarding curvature.

For a reference, Optimal Flight predicts 27.8 yards offline for TorchRedRob's shot below.
Ball ||| VLA ||| HLA ||| Spin |||| SpinAxis ||| Skytrak(Carry) ||| GC2 ||| FTO(Carry) ||| Optimal Flight
166 ||| 14 ||||||| 0 ||||||||| 2083 ||| 16L |||||||||||||| 279 |||||||||||||||||||||||| N/A |||| 286 ||||||||||||||||| 280.6
166 ||| 14 ||||||| 0 ||||||||| 2083 ||| 0 |||||||||||||| N/A|||||||||||||||||||||||| N/A |||| 287 ||||||||||||||||| 284.9

[luv2golf]

Can you or somebody verify it by going to the range and hit s center / center shot and see what the distance offline to center line is. With my hybrid I can barely get over 200 yards and it veers left or right offline by 15 yards either way when hit center/center

But I can hit a 4 iron 210 yards center/ center and be 1-3 yards offline.

I can confirm that skytrak is bang on at the range. I've done at least 15 range sessions this year and each session was bang on. My only issue was when the sun was overhead I had to put a bit of a sun shade (umbrella) over the st to lower the IR impact.

[TorchRedRob]

There have been some people who felt (or witnessed) that Skytrak's curvature is excessive. I felt the same way, but nobody present meaningful data until now (I know it would be extremely difficult to measure curvature outdoors.) My interpretation of shots on Skytrak is to reduce 30% of offline yardages. For example, I see 10 yards left off the target as 7 yards left. I am not saying that my way of reading is correct. FTO doesn't give a number for curvature, but its shot simulation seems to give a lot less curvature. I think Optimal Flight sits in between FTO and Skytrak regarding curvature.

For a reference, Optimal Flight predicts 27.8 yards offline for TorchRedRob's shot below.
Ball ||| VLA ||| HLA ||| Spin |||| SpinAxis ||| Skytrak(Carry) ||| GC2 ||| FTO(Carry) ||| Optimal Flight
166 ||| 14 ||||||| 0 ||||||||| 2083 ||| 16L |||||||||||||| 279 |||||||||||||||||||||||| N/A |||| 286 ||||||||||||||||| 280.6
166 ||| 14 ||||||| 0 ||||||||| 2083 ||| 0 |||||||||||||| N/A|||||||||||||||||||||||| N/A |||| 287 ||||||||||||||||| 284.9

I can say that my own (limited) outdoor testing confirms that Skytrak overestimates curvature. Last winter in the basement, I successfully removed the huge draw I saw on Skytrak. When I went to the range in the early spring, I was hitting pushes that stayed out to the right, yet Skytrak showed them curving back to center or left of center. Ever since, I've been perfectly fine with shots that are left of the line according to Skytrak, since it doesn't happen that way when I am actually outdoors.

[Willymakit]

I can confirm that skytrak is bang on at the range. I've done at least 15 range sessions this year and each session was bang on. My only issue was when the sun was overhead I had to put a bit of a sun shade (umbrella) over the st to lower the IR impact.

So then obviously mine would be a defective then. Because I also did tests on the course and my woods are way off compared to what my lazer would say.

But you still didn't answer my question. Can you or anybody go to the range on your iPad and hit a few balls and see what center/ center comes up with on how far from center line is.

I contacted sky golf this morning. Spend over a half hour for them to tell me that Skytrak will get ahold of me in the next 24 hours. Got a feeling it's going to be a gong show.

Here's my stay on driver. See if these numbers should be correct

105 club head speed. Which I feel is a little low. Been tested at 115 on trackman.

146 mh on ball speed and a little low. Trackman showed me 155-165.

230 yards long with roll. Trackman 275 with roll.

5400 rpm back spin. Very high compared to trackman of 2800.

Now tell me if Skytrak is defective or not.

[TorchRedRob]

So then obviously mine would be a defective then. Because I also did tests on the course and my woods are way off compared to what my lazer would say.

But you still didn't answer my question. Can you or anybody go to the range on your iPad and hit a few balls and see what center/ center comes up with on how far from center line is.

I contacted sky golf this morning. Spend over a half hour for them to tell me that Skytrak will get ahold of me in the next 24 hours. Got a feeling it's going to be a gong show.

Here's my stay on driver. See if these numbers should be correct

105 club head speed. Which I feel is a little low. Been tested at 115 on trackman.

146 mh on ball speed and a little low. Trackman showed me 155-165.

230 yards long with roll. Trackman 275 with roll.

5400 rpm back spin. Very high compared to trackman of 2800.

Now tell me if Skytrak is defective or not.

To answer your first question, I have one screen shot that shows center/center, and the ball was 11 yds left of centerline at 275 yds total distance. It started a little left, and it also curved a little left.

To answer your second question- if you know that you are 10-20 mph lower on ball speed that you are on trackman, using the same type balls, same driver, etc. Then, it is possible that your Skytrak is not right. BUT, first I would make darn sure that it is level and that you tee the ball up about 1 inch behind the red dot. If you tee the ball really high, then perhaps raise the Skytrak up an inch or so above the teeing ground, while keeping the ball the same distance away from the unit. If it still reads low, then there you go. Also, do you have a friend that knows their numbers? If so, ask them to warm up and hit a few balls. If they experience the same reduction in ball speed, then there you go.

More thoughts in general regarding "Center":
when v1.7 came out, this was one of the features:
"-- Added a "Center" reading for side angle and side spin when it's under certain parameters"
We just need to know what "Certain parameters" means. Perhaps "center" is 1 degree or something when it should be more like 0.5 degree to better fit most peoples definition of "center." It's all relative.

But just for the heck of it, let's look at the math:
If you hit a straight push/pull (no side spin), then for every 1 degree that you push or pull it, you'll be 3.5 yds from the centerline at 200 yds downrange. Add in some overestimated curvature, and sure, you'd be offline by some amount.