There comes a time when time is up for an England captain. The main factor is always results but form, fitness, familiarity and just the feeling that enough is enough all play their part.
Michael Vaughan is an extremely smart man who is among the most astute and accomplished of all England captains. There have been 77 of them, and he would be in all top 10 lists and most top fives. He will be fully aware that a debate is being conducted about his position. It might not yet have reached selectors' meetings but outside that rarefied atmosphere, in the real world, it is a hot topic.
To raise the issue seems almost treason. This is the man who did what it was plausible to suggest might never be done again, and the image of him, finally, kissing a replica of the Ashes urn at The Oval on that balmy September day only three years ago will live forever.
But it is being raised, it is being discussed, it is being dissected. England have lost two of their past three series under Vaughanand won the third having to come from behind. His form has grown steadily worse, his series batting averages since his comeback from serious injury a year ago being 62.75, 49.17, 35.83 and 20.50.
If Vaughan has discerned the argument, he claimed to want no part of it. He was, as always, in extremely affable form at the National Performance Centre in Loughborough last week but, if he at all approached prickliness, it was on that subject.
"I honestly don't give a damn what anyone says about that because what will be will be," he said. "I am doing it to the best of my ability, I am trying to build a team to compete with the best teams in the world. We have just won a very good series against New Zealand and there aren't many times England have come from behind away from home and won. There are some real positive signs among the team."
Captains, even those as cute as Vaughan, tend not to know when to go. Of recent vintage, Nasser Hussain seemed to have got it right when five years ago he handed over to Vaughan. As Hussain was to write in his autobiography: "I felt deep down, that I was done... You only want to be captain if people want you to be." Yet Vaughan, to whom he handed over, said only last year that he was nowhere near ready, the implication being Hussain should have stayed on awhile.
Michael Atherton made up his mind to give up after the last Test of the 1997 Ashes series, was talked out of it and regretted it, as he also revealed in his book. "I made some bad decisions as England captain – when you make several hundred decisions a day it's hard not to – but not resigning after the last Test of the 1997 Ashes series was by far the worst," Atherton wrote.
It is a hard job to leave. Far better, or at least easier, to allow others to make the decision. It is what selectors are for, a point the new quartet might remember.
Two significant considerations will be playing on Vaughan's mind: the fact that this week he will overtake Hussain as the man who has led England the second highest number of times at 46, putting him only seven behind Atherton; and that injury deprived him of the opportunity to defend the Ashes in 2006-07 and that he craves one more go.
By the time the 2009 Ashes are done, he might conceivably have led England in 65 Test matches. The whole topic is complicated by his long lay-off with a knee injury that still requires careful management. He missed 16 consecutive matches, but the selectors still insisted he was captain. It was an odd period of limbo which led to a 5-0 Ashes reversal and paradoxically reinforced Vaughan's position. Around the team now he exudes easy authority, but you wonder if this might stray into the divine right of kings territory.
There is no question that Vaughan wants to hang on and that he believes he is doing so for the right reasons. "Part of this job is dealing with a lot of the external stuff, and a lot of that is people writing and saying stuff about the captain," he said correctly. "They're possibly not looking at it in the best interests of the England team. There will be a time when there is a right time but I honestly feel this isn't it.
"I've always said I'll be a better captain the longer I go because of the experience I have and the situations you're put in. I'll probably be at my best as captain when I'm about 45 and sat in an armchair at home."
Of course, like his critics, Vaughan has to ask himself if his continued presence is in the team's best interests. He has expressed a wish to mentor his successor, but is that merely a way of extending his own era? That there is no obvious candidate is never a decent reason for staying on, and it is not as though the England captain, like the MCC president, can name his own successor and therefore mentor him.
Vaughan is short of runs and understands this could do for him. England are playing six batsmen and four bowlers at present, possibly one too many and one too few. Were they to alter the system it would be Vaughan,more than anybody, who would be under scrutiny. It is perhaps cynical but it makes it more straightforward for him, therefore, to have become a proponent of the six-four approach.
He will bat at three in the forthcoming series against New Zealand having opened in the previous six Tests. While openeris his natural berth, he prefers three as captain. "I'm under pressure because I didn't score runs in the series in New Zealand, but over the last year I think in the 12 games I have played I have averaged 43 with two hundreds." Actually, he averages 40, and the brutal truth is that as captain his average is 37, not auspicious in these days of 50-plus figures.
It would be just like him to score runs at Lord's and equal Graham Gooch's six Test hundreds there. He claims good form despite lack of early-season runs. England seem happy with him, but they have to be sure. In terms of the captaincy, above all, they are now picking a team not only for this week but for next year.