The PGA Tour had signalled this was coming, but overnight the R&A and USGA made it official. Golf’s governing bodies announced the creation of a Model Local Rule (MLR G-11), set to go into effect on January 1, 2022, that allows tournament organisers to require players use only approved yardage books in competition.

In turn the PGA Tour can issue official yardage books to players and caddies at tour events starting in January in which the diagrams of putting greens will show only minimal detail, thereby limiting the use of green-reading materials that have currently been at players’ disposals.

According to the R&A and USGA, the MLR 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”. A USGA official said the association does not intend to use the MLR for USGA qualifiers or any of its amateur championships and does not foresee its use at other elite amateur events. And the rule is not intended for use at local golf tournaments or during recreational play.

PGA Tour officials told players in a memo last month that the purpose of the new rule is to “return to a position where players and caddies use only their skill, judgment and feel along with any information gained through experience, preparation and practice to read the line of play on the putting green”.

The approved yardage books will look similar those used previously on tour today with one main difference: they’ll provide only “general information on slopes and other features” for greens. This differs from the green-reading books that have grown in popularity, which use laser renderings of greens to tell precise breaks in each section of the putting surface.

According to the R&A/USGA announcement, the local rule also limits handwritten notes that players and caddies are allowed to add to the approved yardage books. This was addressed in the PGA Tour memo as well:

“Handwritten notes that could assist with reading the line of play on the putting green will continue to be allowed in the approved book. However, such notes will be restricted to only those made by the player or caddie and must be derived from the experiences or any observations of a ball rolling on a green. This includes observations from a TV broadcast. Transferring previous handwritten notes that also meet the new restrictions into the approved book is allowed. No devices, levels or other technology may be used to gather information to be kept as notes, and no information may be copied from another source into the approved book.”

Approved yardage books will have a designation as such on the cover.

In addition to the PGA Tour, the DP World Tour (formerly the European Tour) also intends to use the MLR starting in January. An LPGA spokesperson told Golf Digest that tour officials have not yet made a decision as to whether they might implement the rule and arre continuing to discuss the matter internally among staff and players.

You can read the R&A and USGA’s FAQ document for other details.