Archive for the ‘Trackman’ category

Club Path for Doppler Radar

July 6th, 2014

A couple of weeks ago, I had someone send me a picture of their computer screen with some Trackman numbers on it. The screen showed a shot with a draw relationship between face and path but with a fade spin axis with a driver.

The person asked what some of the possible explanations could be such as gear effect, etc. I asked if they had used something to mark the face. I think they said no and I rattled off a couple of possibilities as to why this may happen. One of the things I mentioned was that the way Trackman measures and displays clubpath doesn’t represent what information is going into the ball.

All sorts of hell broke loose.

Before I go on, at one point I mentioned that the way Trackman measured club path was wrong. This was flippant and inaccurate and I apologize for that. What you will see in just a bit is not inaccuracy but a way of measuring that needs to be constantly adjusted by some amount which varies depending on the club and most likely the golfers style.

 

We’ve all read or heard about D Plane which generally details the information the ball receives from the club to determine it’s flight. This model is based on some very specific assumptions that I won’t get into in this post but at the end of the day, isn’t a great predictive model of ball flight once impact is taken into account.

 

One of the big factors in determining ball flight is the club path. This club path is generally described as the 3d movement of the head in terms of left and right and up down. For now, we’ll assume it’s always going forward also. =) This definition is similar to how Trackman and other Doppler radars measure the movement of the head. Based on my understanding, Trackman is measuring the movement of the center of the head as it moves through 3d space. This center of the head or the center of the blob will be different for an iron and a driver. For an iron, that center will be very near the face and for a driver, that center will be an inch or 2 away from the face.

Here’s where the trouble starts. The center of the head is not the piece of the club that runs into the ball. The path of the center of the head will always be different than the path of the face that contacts the ball unless the club is moving in a straight line. The number displayed on the screen to represent club path is very accurate but that number isn’t what the ball experiences.

Here’s an analogy I first heard from Chris Como to help explain what I am saying. Imagine a train going in a circle in counter clockwise direction. The same direction the face is closing for a right handed golfer. Imagine this train has only 2 cars which are the engine and the caboose.  Imagine that the front of the engine is the club face and the back of the caboose is the center of the club head. As the train goes around this circle counter clockwise, the direction of the front of the engine is always more left than the direction of the back of the caboose. Bringing it back to Trackman and the number on the screen. Trackman and other dopplers show the direction of the back of the caboose on the screen. The ball experiences the direction of the front of the engine because that’s the piece that runs into the ball. Surely there are many other factor in determining the final spin axis and flight as well.

Here’s a graph from a simulation done by Sasho MacKenzie showing the difference between the path of the center of the face and the path of the center of the blob for a driver. You can see that based on this simulation and the assumptions provided, the path of the center of the club head is further right than the path of the impact point for a right handed golfer. The path was being measured at 100,000Hz near impact.

Club Path Graph

What does this mean?

 

This means that unless you are adjusting the path number shown by Trackman or other dopplers by some amount, you are teaching off of the incorrect number and you are possibly hurting golfers.

Here’s the good news. For irons, the path of the center of the head number and the path of the impact point will be much more similar. The points are much closer to each other. The other good news is that the adjustment you’ll need to make to the path number on the screen will tend to be a very similar adjustment for that player. Based on the above graph, you can start to get an idea of how much adjustment is needed. As I mentioned, it may not be the same amount for every golfer but it will be something.

 

The thing I find most interesting is that this information is at least 6 months old and is being written from a putting coach (me) that has never owned a Trackman or similar Doppler radar. I’m surprised at how many golf professionals and players that own this device don’t know the information I’ve shared with you. I’m sure at least some people will want to respond to this and have questions about this that I doubt I will be able to answer them all. I will do my best. I’m also sure that this will be shared with those constantly talking about how useful the machine is wanting an explanation. I think the machine is very, very useful after the adjustment to club path is made in the professionals head and probably nothing as portable with it’s accuracy. I do wish that this information was more readily available and offered up as it’s for the betterment of golfers.

Trackman 2 and Flightscope X2 for Sale

October 13th, 2012

Trackman 2 and Flightscope X2 preowned for sale. I know of one of each currently for sale. If you are interested, please email me at john@johngrahamgolf.com and I will forward your email to the selling parties. I currently have no information on the machines but can speak highly of the sellers.

They are both great and respected coaches. Let me know if you’re interested.

 

UPDATE (10-14-12) I now know of a Trackman 3 and an additional Flightscope X2 for sale. Trackman 2 is selling for $13000 and Trackman 3 for $19995.

 

JG

 

7 Nights of the Twitter Academy

December 11th, 2011

Twitter Academy Logo7 Nights of the Twitter Academy. This idea born from Jason Helman is designed to match the Golf Channels 7 Nights of their Academy. It will feature 7 Top Coaches that have extensive Twitter followings. Each night, one of the coaches will showcase a subject specific video with each coach taking on a different subject.

It should be a great opportunity for golfers to get some additional information from some top coaches. It starts tomorrow night, Dec. 12th at 8:00pm and runs for 7 nights. Topics covered will be Putting, Driving, Chipping, Approach Irons, Mid and Long Irons, Bunkers and Club Fitting with the order of information from the green outwards.

I know all of these coaches well and I’m really looking forward to see what they have come up with. I also hope that this starts some kind of regular thing because I think it is a great idea to showcase great information in a medium that is different than where most go to find good golf information. I can tell you from experience that Twitter is one of the best places to go for good golf information and I hope the 7 Nights of the Twitter Academy brings home that point.

Here are a couple trailers to view.

In order to watch the Twitter videos, you’ll want to follow the presenters. Here’s is the order they will appear and their Twitter Usernames so you can follow them. Click on their name to go to their website and their twitter handle to follow them.

December 12th – Rob McGill @golfprorob – Putting

December 13th – Jason Helman @jasonhelmangolf – Greenside Chipping 3 shots

December 14th – Sara Dickson @sara_pga – Bunkers Green side and Fairway

December 15th – Jason Sutton @golfgurutv - Approach Irons

December 16th – Andrew Marr @andrewmarrgolf – Mid and Long Irons

December 17th – Kirk Oguri @kirkoguri – Shaft Fitting, Launch Monitor Info & Benefits

December 18th – Dennis Sales @dennissalesgolf – Closing the week with Driving and TrackMan Data

I hope you watch and enjoy. If you think others might be interested in this, please consider sharing by using the social media buttons below or by forwarding this email to friends.

John Graham’s Recent Trackman Data

September 2nd, 2011

John Graham Top of Back SwingJohn Graham Top of Backswing DriverI mentioned in an earlier post that I was traveling Europe teaching AimPoint Green Reading with my good friend Jamie Donaldson. Right at the end of the trip, I went to Austria to see Christoph Bausek and did some Trackman vs Flightscope X2 testing. The results of those tests can be found by reading this – Trackman vs Flightscope X2

While I was there, I also did a little Trackman hitting myself. I thought it would neat to share. I have nothing to hide and wanted to see how my typical swing numbers compared to the swing I was working on. I wanted to see if there was a real measurable difference or not and how much if there was.

I think it is important for us teachers to feel comfortable sharing information like this.  I am not here to impress anyone but rather to see the difference a swing thought can make in real, measurable results. Here is the data for you to enjoy, snicker, or whatever emotion you want to throw in there. =)

Trackman Data with 6 Iron

Trackman Data with Driver

PGA Tour Ball Speed Data

September 1st, 2011

PGA Tour Ball Speed DataJust thought some of you may want to take a look at some of the data from Trackman. Feel free to copy, save and pass it on if you think someone you know would like it by using the social media buttons.