Multiple major champion Jon Rahm has only had one caddie since turning professional.
And that would be Adam Hayes, who has been carrying the sticks for Rahm since the duo linked up in 2016.
If you didn't know, Hayes is one of the most experienced caddies on the PGA Tour having plied his trade on the North American circuit since 2004.
Prior to caddying for Rahm, he has worked for Tour pros such as Vaughn Taylor, Webb Simpson, Jason Dufner, Ben Crane and Russell Henley.
Hayes has also had a four-year stint working on the LPGA Tour between 1999 and 2003 where he was earning $400 a week.
When did Adam Hayes begin caddying for Jon Rahm?
The duo have been together since mid-2016.
Rahm was on the lookout for an experienced bag man having just turned professional after a distinguished amateur career.
Hayes and Rahm met up first to make sure their personalities didn't clash .
Hayes previously explained: "Jon was obviously a very popular amateur.
"He was sought after and he was going to have success immediately after turning pro.
"He was with the same management group that Phil Mickelson was with and obviously Bones [Jim Mackay] was caddying for Phil at the time still.
"Bones and I were good friends and they were looking for a guy who was, I guess, not too old, not to young, had a lot of experience, could handle Jon and get to know him and kind of grow with Jon.
"I was in the right place at the right time and Bones referred me and the rest is history."
Hayes said getting the job was nerve-wracking but he realised "pretty much right away" Rahm was "on another level".
Chemistry on the golf course
Rahm is known for having a fiery temper and the TV hot mics often pick up the Spaniard dropping a few F-bombs.
Hayes has spoken at length in the past about how the duo interact on the golf course when the going gets tough.
In media interviews, Hayes has explained how he tries to pick the right moment to talk to Rahm.
"When you get out there on the golf course and do something you know you shouldn't have done and you have worked hard not to do, I understand the frustration," Hayes previously told reporters.
"I never judged him for it or held it against him. But him learning to manage it and become better, I would say it' on him. He's done a great job of it. "
It hasn't always been rosy...
Hayes and Rahm were involved in one tense moment during the 2019 Players Championship on the PGA Tour.
Hayes wanted the golfer to lay up on the 11th hole but Rahm disagreed.
"I wouldn’t change that," Hayes previously SCORE Golf.
"That's not one I regret because had I not said anything I think two things would have happened.
"One, I think would have gotten a lot of heat as a caddie for letting my guy hit that shot without saying anything.
"And number two, I think it showed Jon that I wasn’t scared, not necessarily to stand up to him, but I was never going to not speak my mind when I felt strongly about something."
How much does Adam Hayes get paid by Jon Rahm?
The honest answer is: it depends.
There is no true way to calculate how much caddies will make because their earnings depend entirely on performance.
Typically on the PGA Tour, caddies will make 5 per cent of earnings if their player places outside the top-10, 7 per cent if the player finishes inside the top-10 and 10 per cent for a win.
If you used that model for the 2022-2023 season, then Hayes will have earned $540,289 for being Rahm's caddie.
What does Adam Hayes think of Jon Rahm?
Hayes has explained in media interviews Rahm is a fun guy, smart and does his homework.
He has said there is a huge difference between who Rahm is publicly and in private.
Of Rahm, he said: "He's a solid guy and he's been an incredible boss. I judge people by how I know them and the way that they treat me."