If I wanted to annoy Ed Smith, I would tell him he is a better writer than he ever was a cricketer. All the same, it's a pretty compliment: Smith played three Tests for England and scored 34 first-class hundreds for Kent and Middlesex, with a top score of 213. You have to write fairly decent books to top that.

Smith announced his retirement yesterday; poor timing for a man of 31 at a time when cricket is suddenly becoming rich. Last season, under his captaincy, Middlesex won their first leading trophy in 15 years, the Twenty20 Cup.

Smith didn't lead all the way. He broke an ankle in the course of his team's fifth successive victory in all competitions. He did it on six, turning for a second run, and batted on, as you do. He was out for 33 with victory in sight, so it's a scar of honour, if not good sense. He hasn't played since, failing to make the final or Middlesex's jaunt to the Caribbean for the Stanford shindig.

Smith, an occasional contributor to these pages, has always been a writer as much as a cricketer and that sets a man apart in the hurly-burly of sporting battles and dressing-room dynamics.

He has written three well-received books. His 'prentice piece, Playing Hard Ball, compared his experiences in cricket and baseball. He then did a season's diary, one with an awful lot of meat, On And Off The Field. His present book is in many ways remarkable, entitled boldly What Sport Tells Us About Life. The diary deals with 2003, the year he played for England. He made 64 in his first innings; in his last, he was given out leg-before to a ball that would have comfortably cleared the stumps. What sport tells us here is that life is a bitch. He never played for England again.

Thus it was that England lost a player who might have been up for the long haul. He was, in some eyes, a Future England Captain who never made it, a Mike Brearley come again, but better off the back foot. He couldn't break back in; what some call consistency of selection, others call a clique. Smith's was a career that missed its trajectory.

These two upstanding moments of bad luck dominate the landscape of Smith's story, but he prefers to believe that he was deeply lucky: lucky to have played, lucky to have lived the life, lucky to have shared that life with such a wild biodiversity of people, lucky to have faced the constant challenges and sport's brutal win-or-lose simplicities, lucky to take all that experience with him into retirement, lucky to have them to write about when the time comes.

There has always been something ever so slightly indigestible about Smith. He comes from a background of old-fashioned privilege, something he said you must never presume on and never apologise for. He is also unapologetically clever, with a first in history at Cambridge. He doesn't thrust learning in your face, but he has never learnt the democratic art of pretending to be stupid.

But perhaps more importantly, Smith has the natural apartness of the writer, the sense that all activities, no matter how passionately engaged in, are to be analysed and thought over and - most important of all - at some stage and in some form be converted to the page.

He leaves, he says, without envy or regret, but deeply aware of what he will be giving up. Perhaps the most significant of these is “the external validation” of sport: you score a hundred and you're great and no one in the world can deny it. This is one of the things most conspicuously missing for a writer. Because it's a writer Smith is now.

It is the interplay between action and ideas that fascinates him. In What Sport Tells Us About Life, Smith views the 2005 Ashes series from the points of view, in rapid succession, of a Whig historian, an institutional historian, Thomas Carlyle and a counter-factual historian. So far so clever, but Smith then spins the whole thing round to make a series of brilliant points about the way people in sport should understand recent events. In short, he writes of the role of the past in understanding the present and shaping the future.

Smith has plenty of time to contemplate book No4. He is, he says, relishing the risk of starting afresh. He is no longer a cricketer who can write but a writer who once played cricket. What's next? “Something to do with luck.” Good choice: Smith is already an expert, after all. And, as he insists, rightly, on luck of both kinds.