McCall has shrugged off early woes to be among world's elite
Saracens v Leinster, European Rugby Champions Cup Final, St James’ Park, Newcastle, Tomorrow, 5pm
In Brendan Venter's mind, there was only one man who could complete the job he had started at Saracens. The South African's decision to step away in 2010, after just 16 months, shocked everyone, but not as much as the selection of the replacement he and then CEO Edward Griffiths decided upon.
Mark McCall was a hitherto relative unknown in England; albeit a backs coach, his side's ascetic style did not, at the time, appear an enlightening one. Events since then have mocked those portents.
Since his elevation to overall control as Director of Rugby in 2013, the soft-spoken, determined son of Bangor has taken the pre-eminent English club to unprecedented levels of success.
They have won four English titles and two European Cups; this season, they are on the brink of a second double.
Their players back-bone the national side - from Owen Farrell to the Vunipola brothers - while their assistant coaches thrive, first within, then elsewhere; chiefly, Andy Farrell, soon to succeed Joe Schmidt with Ireland.
But McCall's is the steady, firm hand which underpins it all; an Irishman in exile, happily, successfully, emerging from a bruising experience in his homeland to create a dynasty which, he affirms, owes much to the influence of the side they will face in this Saturday's European final.
Looking back now, Venter smiles when asked to explain his choice of his unheralded seer.
"I'd played with him at London Irish in the 1990s, you had Conor O'Shea and David Humphreys there too, Justin Bishop, and it's no surprise these guys all went on to be high-achievers," Venter said from his South African home last night.
"I knew he was a smart guy, one who could take the club where it needed to go. He could be the one in charge but also allow others to make their influence count. And he has no ego.
"It is all about letting the players and coaches improve themselves and each other. I still travel back regularly and everything works the way I hoped it would. And the success speaks for itself."
Venter, a doctor by profession, told us last year that the maxim he applies to medicine - treating the person, not the disease - applies just as easily to rugby.
McCall established this blueprint, engaging pain-staking individual analysis of every player Saracens employed or wished to employ, eking out every inch of their capability.
Evidence gleaned from every phase of play, every set-piece, in matches and training, and parsed by every specialist coach, from there passed on to the players.
McCall has a law degree; clinical research backs up everything he does; all along he radically re-shaped the side's playing style, transforming a famed defensive unit which may have dominated at home but was, until recently, unable to crack Europe.
His side have at once become feared, almost as much as they are disliked - nobody seems to like them but they don't care - all along, McCall maintains an almost stoic, detached air, unwilling to bask in the spotlight.
"Each campaign and with each year our game-plan has evolved and that has been why the team has stayed successful," notes centre Brad Barritt.
"We have never stood still. There has always been a hunger and desire which is led by Mark. And I don't think we have ever concerned ourselves about opinions from outside of our iron dome which we speak about."
McCall's experiences - and one-time inexperience - have shaped who he is and how he is. He is 51 now; strange to think that when he turned 40, his rugby life seemed as good as done for.
As a player, a sturdy centre, he always superseded obstacles - the nickname, "Smalls", a giveaway - from unpromising Bangor in Division 3 of the AIL to a six-year career in green, starting in Dunedin and ending in Pretoria.
His brothers were keen sportsmen, and bigger too, but it was Mark who forged a representative career in rugby and, for a time, cricket. Dad Conn played for Ireland several times and was president of their Union.
His 13 caps produced just one win, befitting a wretched Irish team in that era; even when Ulster broke through in Europe in 1999, a broken collar bone had already ended his playing career, at 32.
Just four years later, he was propelled into the head coach role at Ulster; success soon came, indeed their last trophy success, the 2006 Celtic League, but so too failure.
Now an authority figure surrounded by erstwhile colleagues, the coach floundered; things turned ugly.
The occasional abuse that rained from Ravenhill stands followed him to his kids' mini-rugby mornings and even when his wife was collecting kids from school.
Only this week, Rory Best, then a callow professional and not the strong captain he is now, lamented the fact that his province did not do enough to support him; neither did the dressing-room.
That 2006 success remains Ulster's last; others can draw conclusions with a cursory glance at what both club and exile have achieved since those days which, although they scarred McCall to the extent he may never coach in this country again, also steeled him.
It was too much too young; and so he went abroad, initially to Castres with former team-mate Jeremy Davidson, achieving notable success with a small fish in a big pond, before Venter hand-picked him for Saracens. It was an inspired move.
"Mark has the ability to keep a very level head, no matter what the situation," flanker Michael Rhodes said this week.
"He doesn't get too excited over any particular victory and also doesn't get too upset about a loss. He's able to view any particular situation introspectively, so that's one of his massive strengths.
"Another one is the way he handles and communicates with the players. The players know where they stand, they always know what is expected of them, there's never any confusion around selection or any aspects of play that need to be fixed or paid attention to.
"It's always clear what's needed from you and what he wants from you.
"'Smalls' is not very outspoken and that's the way he likes to keep it.
"I think he doesn't get very animated, as you see on camera on the weekends.
"Behind the scenes, obviously he can let his hair down a bit more away from the cameras and all that.
"All in all, he's quite comfortable in himself."
He is unlikely ever coach to Ireland for then the job would be about him, he is all about the job.
Ireland has spurned him but he has embraced the world.
With the meekest of voices, his accomplishments scream loudest of all.