For the last five years, the top rules experts in golf have come together from around the world to study a jigsaw puzzle.

That's what Thomas Pagel of the USGA refers to as the book more commonly known as the Rules of Golf.

The purpose of these private meetings essentially is to break up the puzzle and start over so the rules make more sense, without losing sight of the tradition or ethos of a game with six centuries behind it. Sessions can last at least eight hours. The singular goal is to make the rules less complicated.

It has not been easy.

''Everyone wants the game to be simple, but it's a complex game,'' Pagel, the USGA's senior director of rules, said in an interview at the Olympics. ''You have a little white ball that can and will go anywhere, and the rules try to handle all those situations. There's always going to be a level of complexity. But how can we modernize the rules so they're easier to understand and easier to apply so golfers can play confidently that they at least understand the basics?''

The group is closing in on its first draft.

Pagel declined to give a timetable, though USGA executive director Mike Davis said it could be released next year. A modern set of rules is still years away. The development was welcomed by top players who have loads of experience and still can't confidently handle a rules issue without calling an official.

''I'd be behind it 100 percent,'' Kevin Kisner said. ''The game is too slow, too hard and there's too many rules. I wouldn't know where to begin with how many rules there should be. I would think as minimal as possible. And we don't need all these dashes and a's and b's and c's. It's too confusing.''

Jordan Spieth recalls getting a Rules of Golf book at a junior tournament with instructions to keep it in his bag for quick reference.

''I never opened it,'' he said.

Neither did Dustin Johnson. He lost out on a chance to win the 2010 PGA Championship for grounding his club in sand that he didn't realize was a bunker. And he won the U.S. Open this year at Oakmont by playing the final seven holes without knowing if he would have to add one penalty stroke to his score.

He's not sure reading the book would have helped.

''The USGA sends you that rule book, but I don't think it's ever made it out from the envelope to the trash can,'' Johnson said. ''There so many rules that don't make any sense. They could make it a lot simpler and a lot better.''

If only it were that simple.

''You can't change one piece because the tentacles ... it's going to break something else,'' he said. ''It's tough to handle something in isolation. So let's look at everything, step back and take the puzzle part and see where we can make improvements.''

The result could be the most comprehensive overhaul of the rules, which in this case might shrink the book.

The first set of rules was published in 1744, but that was specific to one club. As golf grew, and the number of clubs increased, so did the rules. The Royal & Ancient took over and produced a set of rules in 1899, which the USGA adopted. The R&A and USGA issued the first joint code of rules in 1952, and there were significant changes in 1984. Not to be overlooked is the ''Decisions on the Rules of Golf,'' which amounts to a Q&A of specific incidents.

The most recent edition has 1,200 decisions.

''I don't like the size of the book, but it's one of those deals where you try to address the questions that come up,'' Pagel said. ''In the future, how can you provide guidance to committees so they can get to the correct answers without having 1,200 Q&As? And that's one of our objectives.''

The first draft will be made available to everyone, from recreational players to tour administrators to rules gurus. What will follow surely will be the largest comment period ever for the R&A and USGA. ''This is a book that impacts millions of golfers,'' Pagel said. ''They should have the opportunity to comment.''

And then it will be back to work on the puzzle.

Pagel said five years into this project ''we still haven't addressed everything.''

''But we think we can do it more efficiently, perhaps change some outcomes, make them more reasonable and overall simplify the way the rules are written and look at how the rules are delivered,'' he said. ''It's still going to look like golf, feel like golf, still have the challenge of golf. We're going to make it easier for golfers to play by the rules and feel comfortable playing by the rules.

''Golfers want to play by the rules,'' he said. ''They just find it challenging at times for the book to allow them to do that.''