Should Cook think of quitting now?

Next year will mark the 20th anniversary of one of the most famous boxing matches of the modern era, the first fight between Evander Holyfield and Mike Tyson in Las Vegas. I was fortunate enough to be there as Holyfield, a natural cruiserweight on a mission from his God, somehow beat the brooding post-prison Tyson in 11 rounds, breaking him down physically and psychologically long before the end actually came. All of the talk beforehand was about the heart condition that Holyfield had been diagnosed with: the question was not whether Tyson would win - how could he not - but whether Holyfield would survive.

Afterwards there was a press conference in the media tent that the promoter, Don King, had erected behind the MGM Grand Hotel. King was glowing. If there was one thing he loved more than a big fight it was the chance to promote another, and Holyfield's upset win had handed him the rematch on a plate. With the exhausted fighters sat either side of him, King called for the first question. An English journalist, who shall remain nameless, stood up and said something like: "Evander, don't you think that after overcoming your health problems and regaining the heavyweight championship, you should retire… and Mike, now that you've lost again, do you think that you will retire too?"

The look on Don King's face was priceless. At the time, I was with him on that. Who would not want more of what we'd just had: the action… the drama… the eyes of the world on those 12 square feet of ring. But I've thought about it often since, and I see it now as a question with a different meaning. It's not a question about drama or money or what the spectators want. Instead, it's about what is best for the people involved. They are sportsmen but they are also human beings and the needs of one do not always serve the needs of the other.

The post-match presentation at Trent Bridge mirrored such contrasts. There was the moment that Michael Clarke said that the future of the Australian team was in good hands and the camera cut to the balcony, where all of the players were applauding except for Steven Smith, who looked lost in contemplation of what lay ahead. Then there was Alastair Cook wiping away tears that had welled after Clarke's speech. "I've never heard a crowd so quiet to hear two captains speak," said Stuart Broad.

Losing Ashes series can be kryptonite for captains, and Cook understood just how easily their roles could have reversed. On March 29, Clarke had walked off the MCG a hero having made 74 as Australia won the World Cup final. And here he was on August 8, finishing it all - or being told to finish, depending on who you believed.

He had never won an Ashes series in England, and perhaps that kept him going beyond the MCG - the fairy-tale ending, the complete portfolio. The lesson that defeat offered both Clarke and Cook is that the chance to finish as you want presents itself only fleetingly if it presents itself at all.

So back to the question that was asked in that steamy tent in Las Vegas. Should Cook, who, like Holyfield, had rescaled his mountain, think of quitting now too? It seems almost perverse to ask, but why? He has been through a lot, shouldered his burden, and as Clarke could tell him, a lot can happen between March 29 and August 8. It's become a kind of grim tradition that captains, like football managers, go on until circumstances stop them. Cook is only 30. Will he really see it through for the rest of his career? Smith will assume the Australian captaincy at 26. Should he be expected to continue until he retires? Should Joe Root, 24, do the same? Maybe it is time to think about Test match captaincy in a different, more fluid way, as a job that can be survived and passed on, learned from and lived through. Maybe it should be a fixed-term thing.

In the brutal, bottom-line world of boxing, Holyfield and Tyson carried on, of course. Evander had ex-wives and kids galore to support. Tyson had boxing and nothing else. The next time they fought, on a bleak and dangerous night six months later, he bit off a chunk of Holyfield's ear. They both boxed way too long, getting knocked about by guys who weren't fit to lace their boots in the glory days.

The question hung over both of them, as it does over all of sport.