When the USGA and R&A released the first draft of the proposed rules many many months ago, they included a provision to have fixed distances for measuring drop zones. Rather than use club lengths, golfers were going to have to measure out 40 inches, or 80 inches, in order to determine their drop area.

The USGA and R&A sensibly canned that proposal, but the way in which we measure did undergo a small change.

In 2018, players were welcome to use any club in their bag to measure when required. For players with long putters in their bag, this afforded them the opportunity and advantage to reach areas and create larger drop zones than others with standard length putters.

In 2019, the USGA and R&A have chosen to define a “club length” as “the longest club in the player’s bag except that it may not be his or her putter.” Most of the time, the longest club in anyone’s bag is the driver, so for practical purposes (most of the time), a “club length” is the length of a player’s driver.

This change has two main benefits, as the USGA/R&A see it:

  • Players can no longer choose which club to use to measure with based on the situation.
  • Using the longest club for measuring will minimize the inconsistency in the size of a relief area between players, particularly when one player has a long putter and another does not.

Had the USGA and R&A gone with the measurements by inches, this change would have been rather significant, as players would have had to mark their drivers or alignments sticks or something with measurements. Ultimately, though, the change essentially eliminates using a long putter for measurements and forces everyone to use what will probably be their driver for all measurements.

https://www.youtube.com/watch?v=MG4vVXFtI3M