The USGA and R&A are offering a tool to tournament committees to further limit the use of green-reading materials, often referred to as green books.
The governing bodies have made available a Model Local Rule, MLR G-11, which enables a committee to limit players to using only the yardage book that it has approved for use in the competition.
In announcing the rule, the governing bodies made it clear it is intended only for the highest levels of competitive golf and, even then, only for competitions where it is realistic for the committee to undertake an approval process for yardage books. The purpose behind the local rule is to ensure that players and caddies use only their eyes and feel to help them read the line of play on the putting green.
The model local rule, which was developed in response to feedback from several professional tours, will be available starting Jan. 1, 2022.
The precedent set with the local rule starts with establishing the ability for a tournament committee to establish officially approved yardage books for competition that players would be required to use. The committees could limit the detail available in the yardage book, particularly around the greens. In addition, the local rule limits the handwritten notes that players and caddies are allowed to add to the approved yardage book.
In competitions and casual play where the model local rule is not employed, golfers can continue to use green-reading materials consistent with rules updated in 2019.