It has become one of the most familiar sights on the PGA Tour – a player, and often his caddie, with his head buried in a greens book, studying the little arrows that detail slope and can tell a player what their eyes and feet may not.
Yardage books have been around since Jack Nicklaus made use of them in the 1960s but the preponderance of greens books has blossomed in recent years. They are allowed under the Rules of Golf, which modified the size and scale of the books in 2019, but many feel the books diminish one of the game’s innate skills – the ability to read a green.
Equally concerning is the amount of time players spend poring over the books, not just when they are on the putting surface but when they are hitting approach shots. Greens books are used like addendums to yardage books and pace of play suffers.
Is it likely to change?
Probably not.
The USGA and R&A did not ban the books when they reworked the rules two years ago so there’s little reason to think they will be outlawed soon.
“I don’t think it’s talked about in PAC meetings but it’s definitely talked about in the locker room. People hate it.” – Harold Varner III
Augusta National has made its position clear on the matter, not allowing players to use greens books during the Masters, but they are allowed in PGA Tour events and the other major championships.
How big an issue is it among PGA Tour players?
“I don’t think it’s talked about in PAC meetings but it’s definitely talked about in the locker room. People hate it,” said Harold Varner III, a member of the PGA Tour’s Player Advisory Council which deals with such matters.
They may not like it but many players use them with the idea of gathering as much information as possible before playing a shot.
Some prominent players have expressed their desire to see the books banned. Ian Poulter has been among the strongest critics, saying the use of greens books reduces the skill required to read greens properly. He’s right.

Phil Mickelson has said he studies the slope of greens to help him practice more efficiently at home.
Jon Rahm added his voice recently.
“I don’t think they should be allowed. That’s my opinion,” said Rahm, who added his caddie Adam Hayes carries the book in case the players doubt what they see.
“I think being able to read a green and read a break and understand the green is a talent, it’s a skill that can be developed, and by just giving you the information, they’re taking away from the game.”
There is an art to reading greens. Watch Dustin Johnson study a putt from all four sides. But he also consults a greens book.
The books detail how many degrees of slope are in a particular part of the green while also using arrows to show the direction of the slope. If a player is uncertain if a putt goes left or right, the book – based on laser measuring – can answer the question.
The professional game has become increasingly reliant on information – launch angles, spin rates, smash factor – and the greens books are part of that data revolution.
Like most other things, some players want them, others don’t.
“If you watched me over the last handful of years I haven’t used a yardage book in probably five or six years, and I have never used a greens book,” Billy Horschel said.
“I don’t carry a greens book, my caddy may carry one and I may look at the book once in a blue moon – and I mean once in a blue moon, it could be once in a Halley’s Comet. But I’m a really good greens reader.
“I think you have great green readers and great putters that are just sort of innately that way. And you have some guys that have that skill and they get better with practice and learning some stuff.”

In recent years, players have added the greens book to their calculations on approach shots. The books help players determine precisely where they intend to land shots on the green to utilize the slopes.
In his impressive victory at the RBC Heritage last week, Stewart Cink and his caddie/son, Reagan, talked over every shot in detail. It didn’t promote a brisk pace of play and they didn’t use the greens book on every hole. It was there when they needed it.
“I don’t have a strong feeling, whether they should or shouldn’t be allowed … if you put me in a corner I would probably say they shouldn’t be allowed,” Cink said.
“I think they are very informative. I use one, although I don’t really rely on it that much. I use it as sort of a last-minute check or If we’re undecided about something.”
Collin Morikawa used a greens book during his college career at California but got away from them when he started on the PGA Tour. He went back to using the books last year at the Workday Charity Open at Muirfield Village – and he won.
“I use them because they’re available. I use them a lot more on my approach shots than on my putting,” Morikawa said.
“Do I use it for putts? Absolutely. Do I think they should be a part of the game? I think it takes a skill out of the game. It’s a blending of what you see, how you see the putt, with your caddie. But since it’s available I’m going to use it.”
Rory McIlroy has talked about the danger of the modern game becoming more about athleticism than artistry. He’s on record saying he would ban them completely though he’s used them because they are available.
Until recently, players used their senses – not a detailed drawing – to study the putting surfaces. They use their eyes and feet. They still do but with more information.
“I’m just old school like being able to feel it in your feet, you know, seeing it,” Varner said.
“I can’t find out if it’s actually an advantage. Everybody says we should get rid of greens books but when I look at it, it still doesn’t tell me how far I need to aim left or right.”