SkyTrak Driver Carry Distance (Again)

[AnthonyZ]

SkyTrak – Driver Distance
I understand from reading numerous threads on this forum that a number of us have found that SkyTrak measures Driver (and for some iron) carry distances significantly shorter than measured under real life course conditions or as measured by launch monitors such as Trackman and Foresight - GCQuad or GC2. That has been my experience as well. (A number of people also claim that SkyTrak is accurate if set-up correctly).

During the winter months I practiced and took lessons at an indoor range that has a TrackMan and a GC2 and I could consistently generate a driver ball speed of 132 to 141 mph (club head speed of 90 to 96 mph) and carry distances ranging between 220 to 240 yards. I also tested my SkyPro and found that it fairly accurately measures club head speed. We all know that ball speed trumps club head speed for generating carry distance.

I am pretty convinced that my SkyTrak set at my locale 500-feet of elevation is under calculating driver ball speed by approximately 8 mph which translates to a loss of approximately 15 to 20-yards of carry distance for my driver swing attributes. (With my 7-iron, I am seeing 130-yards of carry distance whereas I should be seeing 140-145 yards of carry on well struck shots with a club head speed of 75-78 mph on Trackman and GC2). SkyTrak set at an elevation of 5,000-feet tends to generate more realistic driver carry distances (albeit flight height, side spin and descent angle should be lower if the SkyTrak algorithm simulates the effect of thinner air accurately).

I decided to run a few tests in outdoor conditions and made sure that my SkyTrak was/had:

• Reset - SkyTrak little hole on the bottom;
• Mat and SkyTrak are dead level;
• Lined-up to target;
• SkyTrak level with base of the mat;
• Clean lens;
• Laser pointed at the base of the tee or slightly forward;
• Black Tees;
• No reflective background; and
• No direct exposure to sunlight.

Baseline – SkyTrak vs. TrajectoWare 1.0
I ran a baseline sample of 12 of my better drives (on a bit of a lethargic early Friday evening) on SkyTrak and compared it to the results that TrajectoWare 1.0 generated and found the carry distance on average to be within 2-yards. In both SkyTrak and TrajectoWare 1.0, I used the Greater Toronto Area elevation of approximately 500-feet, temperature 80 degrees F, and 0 mph wind conditions. I used Bridgestone e6 Soft and TaylorMade Project (a) balls. (TrajectoWare 1.0 is freeware developed by Dave Tutleman and Frank Schmidberger that unfortunately doesn’t appear to be available any longer). I input the SkyTrak – ball speed, launch angle, back and side spin data into TrajectoWare 1.0. SkyTrak calculated an average ball speed of 129 mph and 213 yards of carry distance relative to 215 yards carry distance calculated by TrajectoWare 1.0 or a small difference of 2-yards. (I know that SkyTrak club head speed is at best an approximation but I was surprised that TrajectoWare 1.0 generated the same average 87 mph).

During this session, I used my SkyPro which measured an average club-head speed of 90 mph (club-head speed ranged between 89 to 94 mph). Plugging in an average club head speed of 90 mph and from the table below, the average SkyTrak launch angle of 19.3 degrees, spin of 2530 rpm, side spin of -122 rpm into TrajectoWare 1.0 generated a ball speed of 134 mph and 230 yards of carry distance or an increase of 17-yards relative to what SkyTrak measured.

SkyTrak - 500 Feet Elevation, 80 F, 0 mph Wind									TrajectoWare Drive 1.0 - 500 Feet Elevation, 80 F, 0 mph Wind
SHOT	BALL	LAUNCH	BACK	SIDE	SIDE	OFFLINE	CARRY	CLUB	CLUB	CLUB MPH	CARRY	CARRY
# DRIVER	MPH	DEG	RPM	RPM	DEG	YD	YD	MPH	MPH	DIFF.	YD	YD DIFF.
1	125	17.8	2120	-152	-5.6	-31	208	84	84	0	205	-3
2	127	21.4	2477	106	3.3	19	214	86	86	0	218	4
3	127	23.1	2921	293	1.6	18	208	87	86	-1	216	8
4	128	19.3	2725	-432	4.8	4	212	87	87	0	216	4
5	129	21.9	3109	312	4.6	32	211	89	88	-1	219	8
6	131	20.8	2855	122	3.4	21	219	89	89	0	225	6
7	127	16	2724	273	-3.9	-6	205	87	86	-1	208	3
8	127	19.7	2002	-715	0	-34	213	86	86	0	208	-5
9	131	19.9	2019	-786	-3.6	-55	219	88	88	0	219	0
10	131	15.8	2340	-440	-3.7	-36	215	89	88	-1	214	-1
11	131	17.4	2929	294	-1.8	4	215	89	89	0	221	6
12	129	18.3	2140	-339	-3.7	-33	218	87	87	0	216	-2
AVG	129	19.3	2530	-122	-0.4	-8	213	87	87	0	215	2
Median	129	19.5	2601	-23	-0.9	-1	214	87	87	0	216	3
Min'm	125	15.8	2002	-786	-5.6	-55	205	84	84	-1	205	-5
Max'm	131	23.1	3109	312	4.8	32	219	89	89	0	225	8

Calibration – SkyTrak Elevation to Approximate Realistic Carry Distance
According to Titliest (https://www.titleist.com/teamtitleis...l-aerodynamics), the percentage distance increase (relative to sea level) for drives can be calculated by multiplying the elevation (in feet) by 0.00116. For example, the SkyTrak average drive (table above) that carried 213 yards at 500 feet elevation should see an increase of 12 yards at an elevation increase of 4,500 feet (4,500 x 0.00116 = 5.22%) for a total carry distance of approximately 225 yards.

The table below illustrates that a 4,500 foot in increase in SkyTrak elevation yields driver carry distances that should be expected at an elevation of 500-foot setting. (TrajectoWare 1.0 checked). Setting SkyTrak at an elevation of 5,000 feet (increase of 4,500 feet) yielded an average gain in carry distance of 14-yards to 19-yards or a carry distance of 227-yards which is more inline with a club head speed of 90-91 mph as measured by SkyPro (and a smash factor of 1.45+).

I iteratively solved for ball speed using TrajectoWare 1.0 (set at an elevation of 500-feet). I input the SkyTrak measured launch angle, back and side spin and adjusted the ball speed in TrajectoWare 1.0 till it matched the 5,000 elevation carry distance measured by SkyTrak. On average, TrajectoWare 1.0 estimates that SkyTrak under estimated ball speed by 8 mph at 500-foot elevation. The table also reports that TrajectoWare 1.0 calculated a club head speed of 91 mph which is in line with an average carry distance of 227-yards and the approximate 90-mph club head speed measured by SkyPro.

SkyTrak - 5000' Elevation, 80 F, 0 mph Wind								TrajectoWare Drive 1.0-500' Elevation, 80 F, 0 mph Wind
SHOT	BALL	LAUNCH	BACK	SIDE	SIDE	OFFLINE	CARRY	BALL	CLUB	BALL MPH
# DRIVER	MPH	DEG	RPM	RPM	DEG	YD	YD	MPH	MPH	DIFF.
1	121	20	2125	61	0	3	220	131	88	10
2	130	16.9	2326	-506	-1.9	-29	232	139	94	9
3	125	19.4	2013	-202	-5.9	-36	228	134	90	9
4	125	16.2	2515	252	-3.7	-7	216	132	89	7
5	126	22	2039	-599	1.7	-22	227	134	90	8
6	124	22.3	2284	-295	1.7	-6	223	132	90	8
7	125	21.8	2209	95	-1.7	-3	225	133	89	8
8	131	18.2	2544	-403	-1.7	-26	233	138	93	7
9	127	20.3	2886	165	1.6	13	223	134	91	7
10	130	17.7	2332	-268	-3.6	-29	232	138	93	8
11	127	19.6	2058	326	-5.3	-8	229	136	91	9
12	130	20.1	2647	227	-5.3	-15	230	136	92	6
AVG	127	19.5	2332	-96	-2.0	-14	227	135	91	8
Median	127	19.8	2305	-70.5	-1.8	-11.5	228	134	90	8
Min'm	121	16.2	2013	-599	-5.9	-36	216	131	88	6
Max'm	131	22.3	2886	326	1.7	13	233	139	94	10

I appreciate the above wasn’t an easy read or of particular interest to many, but I would be interested in hearing if you are experiencing similar ball speed and carry distance discrepancies.

[3on3putt]

Have you ever tried using your Skytrak indoors? If it really is coming up short, it's likely due to the outdoor environment.

Just out of curiosity ... what's your handicap?

[3on3putt]

At the end of the day, Skytrak is not 15 yards short. It just plain isn't. If it were, they wouldn't have been in business as long as they have. And if it were, then theoretically all Skytraks units should be just as short. Mine is very accurate. So if it's a Skytrak thing, then why is mine accurate but yours isn't?

There's something else at play here.

[Morini]

No, there is 8+ mph ball speed missing, that is the issue. Hopefully he will figure it out. Any one unit can have issues, but in the vast majority of cases, ST is accurate within stated margin of error. Anthony, if you manage to hit one in the middle of the face with launch about two degrees above static loft, mid 2K spin, and negligible spin axis, please give us the ball speed. If it is not up, I will eat an old headcover.

[AnthonyZ]

Thank you both for your thoughts! I am comforted knowing that SkyTrak is pretty accurate. Morini as to my scientific mindset -- my wife would tell you that I have OCD ;-). Her take is - "maybe you don't hit the ball as far as you think -- isn't that common amongst men?"

Hopefully I get my unit sorted out. Other than carry distance -- the more I learn about the functionality of SkyTrak the more I like it. I quite like the skill improvement add on where you can set up pin distances by club. Using it groove a swing to draw or fade a ball, hit high or low 50-70 yard spinners and test different brands of golf balls -- all kind of fun!

I will report back over the weekend with updated results.

[AnthonyZ]

I may be eating a bit of “crow”, I took another crack at seeing if my Driver – Ball Speed might improve, doing the following:

• Set SkyTrak at 500’ elevation, used the “spin axis” setting (as suggest by @Morini);
• Same PING G400 SFT Driver set at 10-degrees loft;
• Switched out my Regular Flex - Aldila X-Torsion Copper for a Regular Flex - PING Tour 65 (which is a stiffer lower launch shaft); and
• Brand new Snell MTX-B balls (very Pro V1x like).

I picked-up 4 mph of Ball Speed (133 mph) and 15-yards of Carry Distance (228-yard) with the same 19.3-degree Launch Angle, but with 339 rpm less back spin (2191 rpm). The PING chart that was recommended by DS12 puts 130 mph ball speed, 19.2 degrees launch angle with 2000 rpm of spin at 225-yards of carry which suggests SkyTrak is pretty darn close.

I will be playing my first round on Wednesday (courses opened on the 16^th here in Ontario). My Motocaddy M5-Connect power trolley/cart integrates with MotoCaddy’s APP which can measure total distance, hopefully I hit some good drives 😊 in the plus 250-yards total distance.

Here are the results:

SHOT	HAND	BALL	LAUNCH	BACK	SIDE	SIDE	OFFLINE	CARRY
#	L/R	MPH	DEG	RPM	RPM	DEG	YD	YD
DRIVER
1	R	133	17.8	1942	-570	1.7	-21	226
2	R	129	19.4	2167	31	-1.8	-7	222
3	R	135	16.8	2728	-234	-3.8	-27	227
4	R	132	22.4	2020	-116	3.3	9	235
5	R	136	17.3	2038	-662	0	-34	230
6	R	131	20.2	1983	-402	-3.6	-38	227
7	R	131	20.9	2341	168	0	8	227
8	R	133	16.6	2738	-53	-1.8	-10	223
9	R	130	22.2	2013	202	0	11	230
10	R	136	19	1942	-570	-3.8	-49	236
AVG		133	19.3	2191	-221	-1.0	-16	228

[Burtgolf]

This last group of shots .. these are showing much more consistent strike than your first chart. Even though these 10 were better than your other ones just quickly looking at 3 and 8 those were probably low on the face, 4 and 7 were high on the face. There is still some room for you to get that strike more centered. Which would give you much better results in the end!

I would still be interested to see if you tried the powdered foot spray. I find when you do that and check it for a few shots it really helps you focus on your strike. Wipe it off after a few hits, spray it again, let it dry and try another set of 5. I would not even look at the SkyTrak numbers until you get one center in the face.

[Morini]

Happy to hear about the improvement. Have fun out on the course.

Now please hit one with 14 launch angle so you can pick up the other 4 mph so I don't have to eat that headcover.

[3on3putt]

So in other words ... skytrak was right all along? Lol glad you got it figured out.

[AnthonyZ]

Thank you Gents!

@Burtgolf – you right about #3 & 8. #3 & #8 would have optimally had a spin rate of 2300 rpm and 4 & 7 optimally around 1850 (I really like the PING Optimal Launch & Spin Chart). I have not tried footspray yet but ordered LongShot Golf Standard Wood Roll from Amazon (it shouldn’t affect spin like tape would on an iron).

@Morini – I will try my best, I need a bit more practice with my driver before I start hitting the club face just above centre with any consistency. I routinely address the ball with my Driver with a backward (or negative) shaft lean, I will try with a more neutral shaft angle.

@3on3putt – the shots above were about the best carry distances I have hit yet with my SkyTrak! I wonder if it had much to do with using the Axis setting that Morini suggested or I simply had a better go at it? We will see what happens on the course tomorrow. (As an aside, the shots above, I warmed up first with an 8-iron and generated about 98 mph of ball speed and 138 yards of carry which I would be happy with on the course).

[Morini]

Hi Anthony,

Please don't mess with your swing to accommodate me. I just wanted to see where your missing ball speed went.

Changing to spin axis won't change the ball speed. It just makes it a bit easier to see what kind of contact you made. I could use your side spin and back spin to calculate spin axis and spin if I had to.

[LeadZeppelin]

I’m experiencing the exact same thing although my numbers are different the percentage is the same. Thanks for all the hard work and hopefully the algorithm will be corrected. Until then I am adding 5k to my altitude

LeadZeppelin