This week David Moyes celebrates a decade as Everton manager - a feat that grows harder to achieve each year.
Moyes is the third longest-serving manager in the Football League, behind Alex Ferguson and Arsene Wenger.
Fourth-placed John Still of Dagenham and Redbridge is the only other boss to have passed the six-year mark.
Everybody knows managers are getting less time. Last season, the average tenure was 18 months, compared to three and a half years in 1992.
But what is absolutely startling is the number of clubs chopping and changing on a yearly basis.
Remember when Harry Redknapp took over at Spurs? Seems quite recent doesn't it? Not in football manager years, it wasn't.
It was 26 October 2008, and means Redknapp cracks the top 10 longest-serving bosses in professional football.
Of the 92 managers in the Football League:
86% have been in charge less than three years.
49% have been in charge less than a year.
10% have been in charge less than a month.
Incredibly, since Martin O'Neill's appointment as Sunderland boss in December, another 16 clubs have changed their manager.
I'm not averse to a quick sacking if the wrong man is clearly in the job - the penalties for relegation are too great to hang around waiting for the gaffer to come good.
As in any line of work, there are some incompetent people out there, and there is no reason why any club reaching this conclusion should wait.
But the sheer scale of the chopping and changing shows it is not just the bumbling and the out-of-their-depth on whom the axe falls.
As LMA chief Richard Bevan said in relation to Chelsea's sacking of Andre Villas-Boas, constant changes reflect badly on the clubs, not the managers.
Bevan said that Roman Abramovich: "Looking for his eighth manager in nine years is a serious embarrassment."
And he was right. Chelsea have invested tens of millions in top bosses, then refused to give them time to prove (or disprove) themselves.
Even when they did well, like Carlo Ancelotti, they were hoist with the petard of their previous success.
It seems that unless managers deliver constant improvement, they are doomed.
But constant improvement, obviously, is a very hard thing to attain. And for every club going up, there is one on the way down.
That's why it is so good to see Moyes still at Goodison Park.
In his decade, the club have won no trophies, and made little obvious progress in their league performance.
Here are their Premier League finishes from Moyes's nine full seasons: 7th, 17th, 4th, 11th, 6th, 5th, 5th, 8th, 7th.
This is not to belittle his tenure. This is a manager doing a good job on a limited budget, and an owner with the sense (and financial imperative) to recognise this.
Moyes also deserves credit for sticking around despite the constraints.
It is not just club chairmen and owners who get caught up in an unrealistic and unseemly scramble for glory - managers can be just as culpable.
Some bosses fall over themselves to tell the world how 'ambitious' they are. No doubt some would have quit Goodison Park after a couple of upper mid-table finishes, claiming they had taken the club as far as they could.
Take the way Mark Hughes walked out on Fulham, citing the club's lack of ambition, only to pitch up six months later in a worse situation a few miles away.
How long would he have put up with Moyes's miniscule transfer kitty? Not long, I suspect. But it is Moyes who will leave the greater legacy in English football.
Moyes has not been infected by the modern disease of shallow aspiration, and neither has his club.
It would be a lie to state glibly that either Moyes or Everton are 'going places', or 'have a bright future'.
Unless some kindly billionaire deposits a large quantity of cash in the coffers, the best they can realistically hope for is more of the same.
But there is something noble and laudable about a manager ignoring the Premier League's ritual hysteria and simply turning up to do a job to the best of his ability.
Long may he continue.
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