Three-time Wimbledon champion John McEnroe credits his father as being the inspiration behind his illustrious career.
JP and John McEnroe share a drink in Belfast
JP still follows his son on the seniors tour (the BlackRock Tour of Champions) and was supporting him at the latest tournament in Belfast.
BBC Radio Five Live's tennis correspondent Jonathan Overend caught up with the duo in Northern Ireland:
Jonathan Overend: What sort of a man is your father and how much of an influence has he been on you?
John McEnroe: He was one of those guys who worked two jobs to get us into the schools he wanted to give us the best possible chance. We started playing tennis when I was about eight and a half. I say it was six months until I started beating him, he says about a year and a half.
A lot of the time you see parents who are upset when their kids beat them and try to deter that from happening. He always seemed to get a kick out of it and just loved being around the sport.
Even if there were times I felt tired of being on the court or vulnerable, he would always say "you can do it". I still have that ringing in my ears. He's always been my biggest support system.
JO: Has he turned out the way you expected JP?
JP McEnroe: We were very, very surprised to have him become the champion he did. When we found out he'd qualified for the main draw of Wimbledon (in 1977), his mother and I were just astounded. Then he went on to reach the semis on Centre Court against Jimmy Connors (which he lost in four sets).
JO: What main piece of advice did you try to impress on John?
JM: Besides not getting upset at officials?
JP: I always encouraged John to do the best he could and that winning is better than losing. We instilled that in all three of our boys.
It was very surprising to me when he went to Wimbledon in that first year and got in those minor scrapes. In the juniors he really didn't get involved in much of that stuff. The juniors call their own lines and John used to give away points to his opponents.
It was a minor bit of a problem, but I'm not sure if he was like Bjorn Borg or Arthur Ashe he would've been the same champion.
JM: The biggest thing my Dad gave me was belief. He believed in me almost more than I believed in myself at times. When I was feeling down he would believe.
JO: What did he say about the minor scrapes?
McEnroe on stage with Pat Cash and Anders Jarryd in Belfast
JM: He used to say "look, you're better than these people, you don't have to do this stuff, just go out and play". But it was the way he said it.
My Dad is not the calmest guy either, he's got a temper. It was, let's say, a loud dinner table when I was a kid.
JP: I'm Irish - my parents were both born in Ireland. I have a bit of a temper at times. Our dinner table conversation could be, at times, a little more than sotto voce.
JO: How special has it been to come to Ireland, considering your ancestry?
JP: I've been to Ireland a number of times. I was particularly happy when we played Davis Cup in the Republic of Ireland and John was on the team and Patrick was the practice partner.
But this is the first time we've been to Northern Ireland together. John was kind enough to invite me to come and I said "absolutely", and here we are.
JM: It's the first time I've ever been in this area. To be able to come here now, when things seem to be normalised, and then seeing the places where the marches took place, where the problems were, is quite sobering.
JO: Is there anything John didn't achieve that he should have?
JP: There's one thing he didn't achieve he says he would've liked to is win that French Open. Sure I would've preferred him to win it rather than not, but it doesn't matter.
JO: How proud are you of what John's achieved throughout his career? And is there something you would have liked him to achieve that he didn't?
JP: Of course I'm proud of him and always have been. I love the fact he was a Davis Cup supporter and best Davis Cup player in the history of the United States. All of those things I'm very proud of.
And he's still playing...
JM: He asks me every couple of months "is there a chance you'll play Wimbledon one more time?" And he's not talking about doubles. I say "listen Dad, are you aware they still play best of five sets?" He believes in me this much.
JP: Don't believe any of that, because I have never said that, although I believe he could play in the doubles.
JO: Does the speed with which Andy Murray has made the top 10 surprise you?
JM: I'm not really that surprised, because he's grown. You don't see a lot of guys who have the ability to make you scratch your head and think "that's so easy". I'll be surprised if he's not in the top five by Wimbledon. I believe he'll be in the top five within six months.
Murray is more natural on a fast court than Nadal. There's no reason for me to think he can't be right there. Then he's got to hit Federer in the leg or something so he doesn't have to play him at Wimbledon.
JO: Roger Federer has just broken Jimmy Connors' record to become the longest reigning world number one. Of all his achievements, where does that one stand?
JM: It's remarkable. Not the fact that he's so good, but the combination of consistency, his fitness levels and desire and absolute will to win every single week.
Because he likes the game so much and enjoys being around the sport, he makes himself available to people. I commend him for that. He really is a class act and deserves this record.