AUGUSTA, Ga. (AP) — The smell of turpentine takes Rory McIlroy back to his roots.

At the golf course where McIlroy grew up in Northern Ireland, there were certain times of the day when juniors were not allowed to play. So the 6-year-old would hang out in a tiny room behind the counter at Holywood Golf Club and pester Michael Bannon, the pro who taught him the game.

"There were vices and grips and all that sort of stuff," McIlroy said. "I would hang out in the back of the shop and just torment him all day until I could go out and play again. There are so many great memories. Anytime I smell White Spirit, it reminds me of Michael. He would teach me how to put grips on clubs and stuff like that. Really, really nice memories."

That's were a relationship was formed, and it has been unshakable. Bannon still has video of McIlroy's natural swing at age 8, into his teens and onto stardom.

He is with him this week at the Masters. He is the only coach McIlroy has ever had.

"Michael knows my swing better than anyone," McIlroy said. "Knows my swing better that me, basically."

The other two members of this current "Big Three" have the same stories, different circumstances. Jordan Spieth and Jason Day have been with the same coach since they first got serious about the game before they were teenagers.

What these coaches lacked in fame, they made up for with passion for the game and their pupils. More than coaches, they are mentors.

Day's life was headed in the wrong direction after his father died. His mother depleted the family savings and borrowed even more to send him to Koralbyn International School in Queensland, where the golf program was run by Colin Swatton. It changed his life. Swatton not only remains his only coach, he is Day's caddie.

"He's taken me from a kid that was getting in fights at home and getting drunk at 12 and not heading in the right direction to a major champion winner," Day said after he won the PGA Championship. "And there's not many coaches that can say that in many sports."

Cameron McCormick also is from Australia. He came over to America in the early 1990s and played golf at a junior college in Kansas, then at Texas Tech. He became a teaching pro and eventually landed a job at Brook Hollow. That was about the time Shawn Spieth felt his 13-year-old son needed formal instruction.

McCormick said Jordan Spieth was "the most talented man he had ever come across."

They did the heavy lifting early, getting Spieth's arms and wrists moving in a different way, and then it was about refining. He learned early on that Spieth was all about competition — and winning. "I haven't beaten him in a short-game competition since he was 13," McCormick said.

The trust they developed is as valuable as any technical coaching.

"The more you're around someone, you get to know them at such a deep level," McCormick said. "There is a greater degree of honesty over time, and it's easier to process. He's good at articulating things to me in ways I understand. There is no message interpretation needed. We can say anything to each other, and it's coming from a place of genuine desire to help for both of us."

McCormick only comes to about 10 tournaments a year, the Masters and other majors included. If something is off, a phone call or a video text is all that's needed.

"It's a deeper level of trust," Spieth said. "If you're switching between people, you're searching for answers versus someone who's seen so many swings of yours. They know your tendencies, and all of our tendencies keep coming up. If you ask any of us, when we get off, it's something that's been off before."

Tiger Woods is on his fourth swing coach as a pro. Bubba Watson has never had one. Jack Nicklaus worked with Jack Grout from his teenage years, and while coaching was not as intensive as it is now, he only saw Grout a few times a year.

"I think it's nice to have someone who knows you — not only knows your golf game, but knows your personality," Nicklaus said. "These guys have had one teacher, and that's great. I think it's nice to have a relationship. Guys that change teachers constantly ... good gracious, you're so much better off if you learn to correct yourself."

All three players buy into the adage of not trying to fix what isn't broken. All three have traded time at No. 1 in the world the last six months. They have won five of the last six majors.

"I feel like with Jordan and Jason, you're seeing more and more guys adopt this approach that if it has worked all the way through your junior and amateur career, these are the people that got us to this stage," McIlroy said. "There's no reason why it's not going to work going forward."