Bringing you insights from the PING Proving Grounds, where our talented team of engineers, researchers, fitting experts and data scientists design and develop the newest product and fitting technologies to help you play better. Using the most advanced tools available, we’ll explain and explore the science behind golf-equipment performance. We’ll separate fact from fiction with the goal of helping you make informed decisions when choosing the PING equipment best suited for maximizing your performance.
Ever since PING founder Karsten Solheim first helped tour professionals find consistent success by fine-tuning the loft and lie of their irons, lie-angle fitting has been the foundation of PING’s fitting process. His legacy lives on today through our iconic Color Code Chart. A properly fit lie angle enables the club to be dynamically flush to the ground during the impact interval and helps align the face square to the target.
When getting fit for irons, it is therefore critical to find a fitter who both understands how to accurately measure lie angle and how to properly utilize this information.
The first step is to accurately measure lie angle. Today, an overwhelming number of tools can be used to measure lie angle, none of which are void of criticisms or imperfections. Radar-based launch monitors face difficulties with their hardware being positioned 10 feet behind the ball – any difficulty measuring the angle of the shaft near impact can throw off the accuracy of its measurement. Camera-based technology, like Foresight’s GC Quad, relies on markers being placed on the face perfectly parallel to the ground. Similarly, the vertical Sharpie line test, popular among many fitters, relies on the line on the ball being placed perfectly perpendicular to the ground. Considering that a 1-minute change on a clock is a change of 6 degrees, and a good lie-angle fitting is to the nearest 1 degree, it can be quite difficult to hand measure lie angle to the accuracy required. If your fitter is going to use the Sharpie test, make sure they are meticulous with the position of the vertical line.
The last, but most time-tested and popular method to measure lie angle is with lie tape. However, even amongst some skilled club fitters, lie tape faces the catchy criticism that “lie tape lies.” This article explores the topic of lie tape’s accuracy and provides guidelines for a trustworthy lie-angle fitting process.
Lie tape has long been a staple for fitters to establish the proper iron lie angle. After applying the tape to the sole of the club, the mark left from an impact with the lie board indicates whether the golfer is within an appropriate lie angle. As demonstrated in the figure below, for a right-handed golfer, a mark toward the heel indicates the lie angle is too upright and a mark toward the toe indicates the lie angle is too flat.
However, the most common complaint is that no matter how far upright you changed the lie angle, a steep over-the-top golfer would always register a toe mark on the lie tape; lie tape must be lying!
We decided to dive into this topic a little deeper. At the PING Proving Grounds, we conducted a test between our state-of-the-art 3D Motion Capture ENSO Lab, which captures the precise movement of the club at 720 frames per second, and the potentially “lying” lie tape. We compared ENSO’s lie angle measurement with the location of the lie-tape mark.
Overall, there was good agreement between the lie tape and ENSO’s absolute lie measurements. When ENSO measured that the toe was significantly down at impact, the lie tape also measured a toe mark. This quickly shows that the lie tape is not lying for extreme over-the-top, toe-down golfers.
A few shots showed significant disagreement though -– which piqued our interest to investigate further. For example, the shot highlighted in the graph above (rectangular box) registered a 2° toe-up lie angle on ENSO, but an impact mark 2 cm toward the toe on the lie tape is consistent with a 7° toe-down measurement. The issue here is that the golfer had a positive angle of attack, so he hit the board at his low point in a toe-down position and then bounced into the ball with a toe-up position moments later. ENSO registered his lie angle at impact, while the lie tape registered his lie angle at initial ground contact.
It is likely that ENSO (effectively the actual lie angle at impact) and lie tape disagree when the ground impact and ball impact do not occur simultaneously. This will happen with impacts high or low on the face and positive angles of attack. With solid impacts, though, the evidence indicates that lie tape does not lie! Inspired by our latest findings, we now refer to lie tape as “diagnostic tape” and a lie board as a "diagnostic board."
The last piece of the puzzle is determining how to properly utilize diagnostic tape during a fitting. Lie-angle fitting should be viewed as a cumulative process – where each successive step along the way influences your final fitting specification.
Step one, the base of the process, leverages PING’s historical fitting data. With a player’s biometric data (height and wrist-to-floor measurement) and PING’s color code chart we can determine a starting lie-angle recommendation. You can explore this now with our WEBFIT fitting tool. Biometric and dynamic fitting data from over 50 years indicates that 95% of golfers fit to within two color codes of their initial recommendation. As such, it is extremely rare that we recommend fitting someone more than two color codes (2° of lie angle) away from their biometric recommendation.
Step two leverages diagnostic tape and allows for further refinement of the lie-angle recommendation. A few solidly struck shots will indicate whether the lie angle should be adjusted either flatter or more upright.
The third and most important step of the process is to evaluate ball flight and assess turf interaction. A launch monitor can prove invaluable in this step by allowing a fitter to accurately assess the spin axis, or side spin on the ball, and dispersion patterns. An experienced PING certified fitter will help guide the golfer into a lie angle that primarily achieves their desired ball flight while also promoting optimal turf interaction with a neutral dynamic lie angle.
The final, often overlooked, step is to monitor on-course performance. Advanced shot-tracking systems, like the Arccos Caddie app, allow you to identify left-right miss tendencies in your iron play, which can be counteracted with the appropriate lie angle. As your swing evolves, you want to make sure that your equipment continues to work for you.
With this blog post, we hope that we have highlighted the importance of fitting for lie angle and shown that, when used correctly, you can trust diagnostic tape to help you Play Your Best.
Chris earned a Bachelor of Arts degree in mathematics from Cornell University in 2017. Chris researches club-ball impact and ball-flight physics, and helps develop new tools to analyze PING performance data.