REPORT #1 8/21/2007
This report documents an OptimalFlight ball flight analysis of questionable distance numbers from a published TrackMan launch monitor session in the Wall Street Journal. Additional data was gathered and OptimalFlight was able to reasonably reverse engineer the ball flight and validate results.
What was done:
The launch conditions of ball speed, spin, and launch angle were entered into OptimalFlight. TrackMan ball flight results were observed to be significantly shorter than expected.
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July 14, 2007 GOLF JOURNAL By JOHN PAUL NEWPORT
TrackMan Launch conditions:
Spin and SpinAxis was translated into BackSpin and SideSpin components for data entry into OptimalFlight:
The updated summary is as follows:
The OptimalFlight’s maximum height ball flight results are within a few yards of actual results and looks good. OptimalFlight says to expect a much longer carry (almost 15 yards!) and a flatter landing angle. Another discrepancy is the Off Target results or Side* Deviation (5.8 yards difference for Driver 1 and 20.6 yard difference for Driver 2).
It is easy to see how one can jump to an ‘early’ conclusion that the TrackMan numbers are questionable. Expected results for carry distance, off target, and landing angle expected are all off.
Let’s review two possible causes and give radar launch monitor systems the benefit of doubt because of their unique in-flight ball tracking capabilities.
Possible Cause #1: Range balls were used, producing shorter than expected results.
· Why: Range balls can have reduced flight properties due to design or condition.
o Insufficient information or data to rule out this cause. The brand, make, or a close-up picture of the range ball (showing it’s condition) is not known.
o Assumption: TrackMan fittings were done with range balls in very good to excellent condition.
Possible Cause #2: Weather data was not properly factored in.
· Why: Wind can shorten a ball flight. Additional data was gathered to explore this further.
o Geographical data from GoogleEarth
o Weather data from www.wunderground.com
Google Earth of Tappan Golf Center.
Note the compass in the bottom left corner, which will come in handy later.
A minature putt-putt green shown in the upper left (within orange circle) permits correlation of the following video image to the 4th or 5th driving range stall from the bottom of the golf center.
A ball flight shot line can be drawn from the driving range stall, where the TrackMan range session was held, out onto the driving range area.
According to www.wunderground.com on 7/12/2007 – 12-3pm time period, the wind direction is coming from the NW direction and hourly wind average is between 7-13 mph.
Tappan zipcode = 10983
Under Detailed History and Climate input area, the July 12, 2007 was entered.
Revisiting the Tappan Golf Center aerial image on right, the wind directional angle at the time of the TrackMan session is approximately 160* degrees (180* is a pure headwind).
This wind directional effect on a golf ball produces shorter flights and land left of target.
OptimalFlight’s ball flight creation tools permits a closer look at how much of an effect it has.
Using GoogleEarth’s Measure tool, this screenshot shows the range of a 225 yard drive.
The historical wind speed and directional data were entered into OptimalFlight and ball flight graphs were re-generated. The top view summary graph was scaled to size and super-imposed on the driving range.
All distance and landing numbers are reasonable and near spot (green shaded results) on except for an additional 13.8 yards of Off Target result observed for Driver #2. This anomaly may have been caused by an unusual gust of wind or a strange flight pattern due to a scuff on the ball’s cover or a combination of both. We’ll never know for certain. The good news with the recreated ball flight, a –6.2 yards off target deviation is much more acceptable and reasonable outcome than –20 yards!
In summary, the possible cause of weather circumstances (wind) has been validated to account for the questionable shorter ball flight by a radar-based ball flight tracking system. Six out of seven ball flight measurements were nearly replicated.
OptimalFlight’s ability to handle environmental variables with basic ball launch conditions can reasonably reverse engineer a ball flight result from radar based systems. Golfers and club-fitters can translate these results to normal weather conditions (ex: the ball will land approximately 15 yards further if no wind was present) and benefit the equipment decision making process in a clearer manner.
A similar approach has also been used to reverse-engineer and validate launch conditions for Mike Dobbyn’s world record drive of 552 yards in a July 2007 tournament! The result? It is very well within Mike’s long drive professional hitting capabilities to make it happen.