Players and coaches who have worked with Ireland head coach Andy Farrell have given an insight into his exceptional motivational and coaching qualities on BBC Sport's Rugby Union Daily podcast.
The 47-year-old has steered Ireland to become the number one ranked team in the world and the squad is two matches away from winning a 2023 Six Nations Grand Slam.
Farrell enjoyed a distinguished rugby league career with Wigan, before switching to rugby union during the latter part of his playing career.
He began his coaching career as an assistant at Saracens, before becoming part of the England backroom set-up in 2012, being appointed as defence coach with Ireland under Joe Schmidt in 2016 and then succeeding the New Zealander after the 2019 World Cup.
Stuart Lancaster had Farrell as his defence coach during his spell as England head coach up to and including the 2015 World Cup.
"As England coach it was important to have someone who could step in for you and had your back," explained Lancaster.
"You could tell he was a leader as a player and as a head coach, you need a strong second voice in the changing room, that person who can take the weight off your shoulders a bit. Andy fulfilled that role for me.
"I think he's a student of sport, of teams and of coaching. A lot of big personalities who have been great players don't have that passion and rely on their playing ability to translate into coaching ability and I don't think that Faz has done that.
"He has got lots of strengths but I think his ultimate strength is the breadth and experience he has in lots of areas.
"It's not just defence it's attack. It's the ability to manage people and he's got the presence and the personality to drive that. He's a great orator so has the ability to inspire and motivate as well."
Taking Ireland to the next level
As a senior coach at Leinster since 2016, Lancaster has continued to work closely with Farrell in his Ireland role and has seen the Irish side develop under his guidance to become a potent force in world rugby.
"Faz inherited very strong foundations from Joe but it was different," said Lancaster. "It would have taken everyone time to adapt and change. Evolution of style takes longer at international level.
"Andy has surrounded himself with good people that you need when you graduate to the number one position. In a coaching team you're looking for that blend of talents.
"He has recruited the best in those areas and been getting the best out of them, making them part of the team and creating a happy environment.
"He has signed a contract with Ireland beyond 2023 so he's still young and who knows what lies ahead for him after that.
"I can't see any reason why he wouldn't be Lions coach in 2025 but as international coaches we know you are judged by your last result so he won't be getting too far ahead of himself.
"The Ireland players won't either as it's a very difficult end to the Six Nations [away to Scotland and home to England]. The pool stages for the World Cup are fraught with problems [with South Africa and Scotland also in Group B] and the draw is loaded on the wrong side [France or New Zealand are likely quarter-final opponents].
"Faz now has that group of players who can really understand the game and properly take ownership. He is good at giving players shared ownership and Ireland have that stability and consistency at international level and provincial level that has benefitted them.
"There's a strong foundation and depth in Ireland in every position, a real sense that they are all on the same page. That's credit to Andy ultimately, because he's the one who has to pull it together."
Former England and Saracens wing Chris Ashton outlined how Farrell "blew his mind" when he introduced training reviews as part of match preparation and emphasises the attention to detail of individual performances which sets him apart.
"We came in off training and he said we had to start reviewing training," said Ashton. "He may not have been the first [to do that] but he was the first for me.
"We trained, then went back to sit in a room and watch what we'd just done. Now it's almost strange if you don't do it.
"Reviewing training helps you see what you were doing right and what you were doing wrong, to understand how and why, and the improvement we saw was dramatic.
"What's so impressive is how he has been able to acquire such a deep understanding of the game without playing it that much, to move to rugby union in the latter stages of his career and then end up coaching and passing on information to players who have been playing all their lives.
"A big thing on his side was how he could speak and motivate people, explain things so clearly. The number of people in the game able to do that are few and far between."
Prop Alex Corbisiero played under Farrell as part of the England squad and on the British and Irish Lions tour to Australia in 2013, in which the tourists won the Test series in a decider.
"The first team talks he gave with England resonated with me," said Corbisiero. "Bringing him into the England fold when Lancaster did was an incredible experience. When he spoke he captivated the room.
"We had a very inexperienced 2012 Six Nations squad, but after his defensive talk you are believing everything he has said, you have harnessed the pictures, the imagery, the tactics, but also the intensity and the mindset.
"If you then put that in the context of the Lions, when you put him in a room with a 'who's who of rugby', it was just an incredible experience.
"He set the tone from the moment he spoke. He talks the talk and he walks the walk. You wanted to please him and you wanted him to be proud of you.
"It was a powerful force to have in your team - the ways he could get men to follow him, believe and buy into what he was saying with just his words. Intensity, resilience and his belief in getting others to follow.
"He's the perfect deliverer of that intensity and he drives it through the week, almost like that General, someone who is spurring you on, his expectation and that 'buy-in', what he expects from you makes you raise your game.
"He's a man of conviction, a strong-willed, opinionated man and he backs up what he says. His power was in the week, explaining what we needed to do, challenging us and driving standards. He was a powerful orator too, a powerful combination.
"He was such a big force in everything we did that it was only a matter of time before he got an opportunity. He was always destined to be a head coach.
"Farrell embodies everything the Lions are about. I'd be shocked if every player going on that 2025 Lions tour to Australia didn't want him as the head coach.
"Steve Borthwick is an incredible coach and England are in a good place in this cycle.
"But if I was at the RFU I'd be waiting for his contract to end to bring him back into the fold. It's England's loss where he is right now. He's building one of the best, if not the best, teams in the world."