Each year the auditions come and go and always there has to be the same conclusion. Yes, of course this is a man equipped to occupy the biggest of stages. Yes, he understands all the nuances of his job, the soothing of a player's psyche, the raw capacity to wheedle and kick a team into an effective performance.
But then when, if ever, will David Moyes make the big breakthrough?
How much longer will the 49-year-old see the big jobs floating across his line of vision and sometimes apparently settling into his palm, only to watch another contender step into his place.
Most starkly, it happened when Chelsea jettisoned their Champions League-winning manager Roberto Di Matteo and dragged back from the wilderness Moyes's old Liverpool rival Rafa Benitez. Typically, the absence of thumbscrews meant that there was no earthly chance the Everton boss would vent his feelings. He'd taken such blows many times before, but this one, it was reasonable to speculate, must have dug deeper.
For so long he had fought Benitez on one of the most uneven fields in all of big-time football. The Spaniard complained of crippling restrictions imposed by Liverpool's American owners, but his spend in the transfer market regularly dwarfed that of Moyes.
Moyes maintained over-achievement at Goodison Park as a matter of course – and waited the call to a more glamorous theatre of action.
It never came – not, anyway, in acceptable terms and timing, and there was Benitez striding eagerly back into the big-time, despite an unprecedentedly hostile reception by the Chelsea fans.
Now, with the Spaniard apparently heading irrecoverably back to the oblivion that came to him in his brief stint as Jose Mourinho's successor at Internazionale, Moyes is believed to be back in the running for the most perilous job in all of football.
But, no, not as a front-runner, but a potential back-up if reported overtures to former boss Mourinho go as badly wrong as those to the hugely favoured Pep Guardiola.
Inevitably, Moyes has kept his silence, but then there is that other certainty. It is that another huge audition is always just around the corner and which one has ever offered more kudos than the one scheduled for Sunday afternoon at Old Trafford? The impact of an Everton double win over the runaway Premier League leaders would surely be profound?
How better to announce your right to wear the shoes of Alex Ferguson than by beating him twice in a season when he moved so relentlessly on the club's record 20th English title?
The effect of Everton's dramatic start to this season with a narrow, but well-deserved victory over United at Goodison still lingers powerfully in the consciousness of the Premier League. It said that Moyes had once again been at his work with superb application and perspective. Once again he had bought low, but with maximum shrewdness.
Everton have underlined the point with their sustained attempt to match the top-four place achieved eight years ago in the shadow of Liverpool's Champions League miracle in Istanbul. They have played strong, muscular, but also inventive football behind the momentum created by arguably the most cost-efficient signing in recent Premier League history, Belgium's £15m Marouane Fellaini. Another Belgian, Kevin Mirallas, has brought impressive weight to attack and, always, there is the promise of decisive action from the experienced Steven Pienaar.
Moyes was thrilled to reclaim Pienaar from Tottenham, saying: "You have to be patient in these situations, but when you know the value of such a player, when you have seen him prove it consistently over the years at club and international level, patience is the least you can ask of yourself."
What Everton, and the rest of England's top flight, have come to expect of Moyes is something rather more than a dogged pursuit of his goals. There is also the perception that his signing of Croatian Nikica Jelavic was the most inspired move of last year's winter transfer window and fresh evidence of remarkable intuition in identifying players from whom he can draw all of their potential.
But has any of it brought him significantly closer to the big moment when a United or a Chelsea announce that he has convinced them that he is equal to any challenge in football?
Some Old Trafford insiders are convinced that Moyes has made his point and that a combination of Mourinho's unruly behaviour in Madrid and Guardiola's decision to accept the offer of Bayern Munich has torn down the last barriers.
"For the longest time," said one of those sources, "it was believed that Mourinho's status as successor to Ferguson was copper-bottomed. He just outstripped the field with his achievements at Internazionale.
"But then he started to cause such uproar in Spain, that there was a shift towards Guardiola, a brilliant coach of fantastic achievement at Barcelona, with people saying: 'Look, Guardiola isn't going to embarrass the club and he is a proven winner.' Now it seems that Moyes has regained pole position in Guardiola's absence."
It is a possibility certain to make the pulse of Ferguson's fellow Glaswegian race. His contract expires next summer. As managerial progress goes, few have ever made free agency quite such a valuable hand. If it happens, no one will be less surprised than his old friend Joe Jordan, the former Leeds United, Manchester United, Milan and Scotland striker, who currently works as Harry Redknapp's coach at QPR.
Jordan and Moyes were at Bristol City at the end of their playing careers and the former recalls: "I've met a lot of committed people in my time, but no one quite like David.
"His immersion in football is complete. You could be up till dawn in the digs we shared and he would still be talking football."
There have been times when it seemed like a lonely obsession, but if it should happen that Everton beat United on Sunday afternoon David Moyes is unlikely to want for company.
Some of it, the consensus is hardening, may well be carrying offers that simply can't be refused.