A Tour Through the Trajectory Software

Hundreds of clubmakers have purchased the TWGT Trajectory and Ball Flight Modeling Software and found it to be extremely accurate in guiding their selection of the best driver loft to maximize ANY golfer’s distance. Even if you own an expensive launch monitor, without the Trajectory software you will not know the best driver loft for maximizing distance unless you build several demos and have the golfer hit every one.

Excuse me if I am blunt. First of all, we did not create it to be a profit center for TWGT. We originally created it to learn more about the relationship and effect of changes in launch parameters in our own R&D. But when it was done, I was so blown away by the information that was possible to glean from the program that I really wanted clubmakers to have access to this information. If you are serious about doing the best job in your fitting, you are missing a huge aid if you don’t own and use a copy of this software.

That’s why I wanted to create a tour of the software on our web site to show you both what it can do, and also, how EASY it is to use. Often, software programs that offer technical information can be intimidating and fall into the category of, “Wow, that’s something else but it looks way too technical for me to learn to use.”

No it’s not! So take a look and see what it has to offer in this overview, and then tell me you wouldn’t do a better job in your fitting.

Part 1 – Getting Acquainted with the TWGT Trajectory and Ball Flight Software

Below is a close-up view of the main screen where everything is done.

NOTE:
clicking on any of the following software screenshots will display a larger image in a new browser window

Look across the top where all of the menu bar selections are located. 4th one over is MODE. If you click on that selection, you’ll see there are four different modeling options available in the program. You’ll primarily use two in your fitting – LAUNCH PARAMETERS and MANUAL CLUB PARAMETERS.

In LAUNCH PARAMETERS you can find out all about the relationship of the three main launch parameters of

In addition, you can find the effect of weather conditions on the outcome of the shot. Inputs to vary the Wind Speed, Air Temperature, Barometric Pressure Reading, Relative Humidity and Elevation are even provided in the box on the right side of the screen.

You can manually enter any combination of any of these launch parameter and weather inputs and find out all of the things shown across the top of the screen in the next image.

Launch Parameters Mode Screen

This example on the screen shows that a shot hit at sea level on an average, nice 70° day, which is launched at a ball speed of 144 mph at an angle of 9.5° with 3200 rpms of backspin will carry 228 yds. It will hang in the air for 6.81 secs, fly 85 feet high at the apex of its trajectory, and roll 23 feet if it landed on a green.

Now, what if this shot were launched at the same angle at the same ball speed, but a driver that could generate less backspin that 3200 rpms were used for this shot. Let’s say a driver that launched the ball at the same 9.5 launch angle at a ball speed of 144 mph, but with only 2200 rpms of backspin. After all, the “rumor” is that low spin hits it farther right?

How about that? There is a 4 yard drop-off in carry distance. Yet the ball speed and launch angle were the same as before when the shot was launched with 3200 rpms of backspin. Less distance is a fact because at a ball speed of 144 mph, 2200 rpms of backspin cannot generate enough lift to move the ball high enough to keep the ball in the air long enough to carry as far.

Well, where do low spin drivers help golfers get more distance? Let’s take a look at that next. In the following run from our Trajectory software we have set up the Launch Parameters mode of the program with a ball velocity of 165 mph, typical for a player with a 110 mph swing speed. In the first run, seen in RED in the screen image above, the 110 mph swing speed.

In the first run, seen in RED in the screen image above, the 110 mph swing speed golfer achieves a carry distance of 258 yds. With the same launch angle, same 165 mph ball velocity but with 1000 rpms less backspin as shown in the GREEN output on the screen, this player gains 1 yard in carry distance to 259 yds, but lowers his trajectory which would likely result in a little more roll on the fairway for greater total distance.

ONLY golfers who can generate a ball speed higher than 155 mph will benefit from using a clubhead or ball that generates lower backspin. This is because at these very high ball speeds, the reduction in backspin brings about less friction between the ball and the air, thus allowing the ball to fly a little farther. What keeps the ball in the air is the much higher ball velocity. Thus, all golfers with a swing speed of 105 mph and lower need more backspin to maximize their distance, while only those players with swing speeds over 105 mph can benefit from less spin on the ball.

Part 2 – Actual Fitting With the Trajectory Software

The Mode of the Trajectory software used by most clubmakers in their actual fitting sessions is the Manual Mode. Let me show you exactly how this works to pinpoint the right fitting specifications for optimizing a golfer’s potential for distance. In addition to the software at the least, you need to have an accurate device to measure the golfer’s swing speed. In addition, being able to measure the golfer’s actual launch angle will make the accuracy of the Trajectory software complete.

If you do not have an expensive launch monitor, not to worry. This is precisely why TWGT developed the Launch Angle Gauge (stock #190-LAUNCH - $59.50) and why we refer to it as “the poor man’s launch monitor”! Thus with a swing speed device, the Launch Angle Gauge and the Trajectory software, you are “in business” for being able to very accurately fit golfers with a driver that will maximize their distance potential.

Step 1 – Obtain the Golfer’s Swing Speed and Launch Angle

The club that the golfer uses to record a swing speed and launch angle can be their current driver or a demo/test driver that you have in your workshop. It will be necessary to know the true loft angle of the clubhead, and not just to trust the loft number engraved on the head.

Step 2 – Determine the Golfer’s Angle of Attack from the Launch Angle Measurement and the Driver Loft

A VERY critical parameter required to accurately determine the best fit for distance is the golfer’s Angle of Attack.

The angle of attack is not the swing path. It is the angle at which the clubhead travels at the end of the downswing to contact the ball. Golfers may have a DOWNWARD, LEVEL or UPWARD angle of attack, and is measured in degrees. The angle of attack is determined by the golfer’s individual swing mechanics.

With the known loft of the test driver and the average launch angle obtained by the golfer with that club, you can reference the following chart to determine the angle of attack.

With the golfer’s swing speed and angle of attack measurements, you are all ready to work with the Trajectory software to pursue the fitting. Open the software and access the Manual Mode from the pull down menu commands.

Upon selecting the Manual Mode of operation, you will input a series of selections as seen on the screen image above by clicking on each selection – COR, Head Weight, Attack Angle, Loft Angle, Head Speed and Club Number being modeled. The Ball Properties is simply an optional input that offers the change to model with general values for different ball construction types. We recommend just leaving the Ball Properties input at its default entry for most of your fitting work.

The result for this combination of inputs is a shot that carries 187 yds. Due to the -3 degree downward angle of attack of the golfer, the launch angle is only 5.0 degrees with a 9 degree loft driver head. Obviously a golfer with a 90 mph swing speed should be able to carry the ball farther than 187 yards, so lets start increasing the loft angle and see what happens.

On the right side of the top of the screen, under the Loft Angle deg. column, you can see the different loft angles that were inputted, one after the other, increasing from 9 degrees to 17 degrees. Look at the carry distance column in the output information. Starting at a carry distance of 187 yards for a 9 degree loft, the distance increases as loft is increased up to a point at 14 degrees, after which the increases are minimal for the increase in launch angle. Thus from the Manual Mode of the Trajectory software, the optimum loft angle for a driver for this specific player would be 14° to maximize distance because the additional 2 yards from a 16° or 17° driver only hits the ball higher, possibly decreasing the roll of the ball.

Let’s try one more example fitting to illustrate how a slower swing speed might not necessarily be best fit with a much higher loft driver, and thus show the importance of being able to model ball flight using the Trajectory software.

The next example is for a golfer with a slower, 80 mph driver swing speed. However, this golfer does what a lot of less skilled players do in their swings and happens to release the wrist-cock early on the downswing and allows the wrists to actually “flex forward” just before impact. If you look at photos of the proper swing movements, the desired position of the wrists at impact is to have the back of the lead hand straight, so that there would be a straight line from the top of the lead arm all the way through the hands, down the shaft to the clubhead. It is very common for less skilled players to not be able to achieve this impact position, and instead, to allow the wrists to “break” forward before impact. When this happens, the angle of attack to the ball will always be in an UPWARD path. Proof of this is that the launch angle will be much higher than the loft of the driver head being hit by the golfer.

Many people assume that all slow swing speed golfers need to have much more loft on the driver to maximize their distance. However, in this case where the golfer makes a common swing error to cause an upward angle of attack to the ball, the optimum driver loft is shown to be 12 degrees.

In looking at the shot examples for this 80 mph golfer with a +5 degree angle of attack, you can see that the carry distance remains the same for lofts from 16 degrees down to 12 degrees. The reason this happens is because for each degree decrease in the loft, the backspin decrease is offset by the ball speed increase. Thus the carry distance remains the same over this 5 degree spread in driver lofts. For this golfer, at a loft of 17 degs and a loft of 11 degs, the distance begins to drop. Thus because the 12 deg driver achieves the same carry distance, but with a LOWER trajectory, the golfer would get the most total distance from the lower trajectory bringing about more roll on the fairway.

Beyond the information clubmakers can learn from the Launch Parameter mode, and the fitting accuracy contained in the Manual mode, the Trajectory software has tons more information that can offer whatever depth of understanding a clubmaker may wish to probe about the real relationship of launch parameters in golf.

But for these simple functions ONLY, the Trajectory software is very easy to use and will increase the accuracy of your fitting to the point that all golfers who come to see you for help with their game, can walk away very pleased from the experience.

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