14 March 2023
Notice to Manufacturers
Proposed Model Local Rule for Elite Competitions to be available beginning
January 2026, requiring the use of golf balls that are tested with modified Actual
Launch Conditions (ALC) within the Overall Distance Standard (ODS)

On 1 February 2021, the USGA and The R&A issued a communication that specified a set of research
topics relating to potential Equipment Rule changes intended to address the findings from the Distance
Insights Report and the Conclusions from the Distance Insights Project: Implications of Hitting Distance inGolf. In summary, the objectives were to identify mechanisms to address the persistent increases inhitting distance over time that have fueled the pace at which golf courses are lengthening, as well as toenhance the reward of a central impact. Further information on additional research areas were detailed in
the March 2022 communication and further refined in June 2022. These communications conveyed
interest in the following:

1. To investigate an increase to the clubhead speed used to determine conformance to the Overall
Distance Standard (ODS) that reflects the clubhead speeds of the longest hitters of the golf ball;
specifically, between 125 and 127 mph. In addition, to investigate the use of optimum conditions oflaunch angle and spin.
2. To investigate the exploration of (i) reduction of the spring-like effect in drivers, and (ii)changes to the Moment of Inertia (MoI) limit of drivers to enhance the reward of a central impact.
This research was specifically focused on Characteristic Time (CT) values for drivers of not morethan 200 µs and not less than 150 µs and a Moment of Inertia as low as 2,000 g-cm2. These
potential changes were investigated specifically in the context of potential Model Local Rules(MLR).
We would like to acknowledge that significant comments were received by stakeholders regarding theseareas of research. All the comments were carefully reviewed and considered in accordance with theEquipment Rulemaking Procedures adopted in November 2011.
Regarding Item 1., based on the feedback received from stakeholders, The R&A and the USGA are nolonger considering the use of launch conditions that are optimized for each individual golf ball model toevaluate conformance. We realize that the use of optimized launch conditions for each ball model may
have caused challenges in the development and testing of golf balls, including significant added cost andtime.
Considering both the industry feedback and further research by the USGA and The R&A, we havealtered our approach, and are now proposing to make available a Model Local Rule (MLR)
intended for elite competitions. Specifically, for this proposed MLR, golf balls will be tested forconformance to the Overall Distance Standard (ODS) limit of 317 yards (plus 3 yards tolerance) at

modified Actual Launch Conditions (ALC), namely a clubhead speed of 127 mph and ALC valuesof 11 degrees and 37 revolutions per second (2220 rpm).
Within the current Equipment Rules, all other golf balls will continue to be evaluated using the existing
ALC values: 120 mph clubhead speed, 10 degrees and 42 revolutions per second (2520 rpm). The
current ODS limit of 317 yards (plus 3 yards tolerance) will remain unchanged.
Equipment Standards testing for all golf balls will have their launch conditions determined by amechanical golfer that has been set up to produce the appropriate launch conditions, as listed above, ona calibration ball.
Please note that interim screening and more efficient means of determining the ALC will be investigated.
In addition, the possibility of reducing or eliminating the Initial Velocity (IV) standard for golf balls (that arenot tested at the MLR conditions listed above) will continue to be evaluated, but no change is being
proposed at this stage.
The Conclusions from the Distance Insights Project noted that the USGA and The R&A were notconsidering changes that would result in substantial reductions in hitting distances at all levels of thegame. The proposed MLR would enable golf event organizers and committees to use specific balls forcertain elite championships and tournaments but would not impact the current recreational game in anyway.
It is proposed that the MLR will be available for implementation on 1 January 2026 (at the earliest).
Regarding item 2 from the March 2022 Notice, and again in consideration of industry feedback, The R&A
and USGA are not pursuing a reduction of the CT limit or changes to the Moment of Inertia limit of drivers
at this time.
While not pursuing a reduction in the CT limit, the USGA and The R&A are concerned that many of
today’s drivers exhibit levels of CT creep – meaning their CT values are appropriate at the point of
manufacturing/initial use, but can become non-conforming after repeated use, especially at the highest
level of competition. This is contrary to the purpose and intent of the Equipment Rules. As such theUSGA and The R&A are undertaking a comprehensive investigation of this phenomenon. Further details
on this topic will be forthcoming in due course.
Comments on the proposal for the Model Local Rule relating to golf ball conformance are due by 14
August 2023.