Rory Best believes Joe Schmidt's true coaching acumen lies in his man management.
Exacting Ireland boss Schmidt has long been revered as a tactical genius, devising one-off special moves to unpick individual defensive weak points.
But now Ireland captain Best has revealed Schmidt's ultimate Midas touch as the ability to confound his players' expectations, to keep them sharp.
Evergreen hooker Best will play his final Guinness Six Nations match in Saturday's Wales clash in Cardiff, but that will also prove head coach Schmidt's tournament farewell.
"There are many shades of Joe; he'll judge the week depending on what he feels we need," said Best.
"Sometimes coming off the back of a good performance he's incredibly hard at you in the early part of the week.
"Sometimes coming off the back of a good performance he can be praise you quite a bit. He mixes it up.
"He's incredibly good at gauging the mood of the group, and how we're going, and what we need to really concentrate on to make sure that we can improve, keep getting better and ultimately win a game tomorrow.
"That's the skill of the man. There are all the plays, the way we go about bits and pieces of our game.
"But the last little bit that's a bit more unseen is just the way he manages people and the way he manages the group as a whole."
Best admitted his 64th and final Six Nations turn will definitely provide several poignant moments, even though Ireland are itching to deny Wales a first Grand Slam since 2012.
The 116-cap Ulster star intends to retire after the autumn's World Cup, and knows full well the privilege the tournament has offered him since his Six Nations debut back in 2006.
Asked if the emotion will creep up on the day, Best said: "There will be moments. When you leave the bedroom for the team meeting, hopping on the bus, during the anthems - those moments dawn on you as the last in a Six Nations game.
"You'll miss the little high bits; that first whistle when the crowd goes bananas, the atmosphere in the changing room after, when everyone is sitting down, absolutely knackered.
"I've always said if I could pick when I want to leave, I want to go on my terms when I am playing well.
"I feel I am playing well at the moment and I'm looking forward to what comes, hopefully, at the end of the year.
"Ultimately I feel now is the time to go and it's an incredible spectacle tomorrow."