JUST as birds skedaddle south for the winter, so the notables and quotables with books and DVDs to punt head for the arenas.

With Christmas coming and letters to Santa being composed there is no time to lose in advertising the merchandise. This year, there is a class act among the usual suspects, a name that is to football what Bill Gates is to computers and Justin Bieber is to tweenies. Welcome to the Sir Alex Ferguson tour of 2013, launched to coincide with the publication of his autobiography at the end of this month.

There is no official, rock band-style tour title, no Steel Wheels, Glass Spider, or Joshua Tree-emblazoned merchandise. It is just the book, a tome plainly titled Alex Ferguson: My Autobiography (lest there be any confusion).

If anything, however, the former boss of Manchester United will be looking to The Boss for inspiration when he travels round Britain and Ireland. As the Yes camp doubtless suspects, Sir Alex's book tour will be less a Born in the USA odyssey than a "Born in Scotland, Proud of It, But Still Agin Independence" trek.

Doubtless the gigs at the Lowry Theatre in Manchester, Royal Festival Hall in London, and Dublin's Convention Centre will be taken up with footballing tales of championships won and players lost to the path of righteousness. Ditto, for the most part, the events in Glasgow and Aberdeen (Clyde Auditorium, no less, and the Music Hall), where Fergie's views on Scotland and Gordon Strachan, and how he thinks the new broom is doing at United, will be far higher up the agenda than matters referendum.

But it would be very odd if such a gut-instinct political operator as Sir Alex visited Scotland without uttering a word about independence. Indeed, being resident in England, and therefore without a vote next September, this would be the perfect opportunity for Fergie to have a say of sorts outside of the money he has already donated to Better Together (£501, a quid over the limit suggested by the Yes campaign for donations from those resident outside Scotland but within the UK).

When he made that donation, Sir Alex had a message for the other Alex, First Minister of this parish, saying: "Eight hundred thousand Scots, like me, live and work in other parts of the United Kingdom. We don't live in a foreign country; we are just in another part of the family of the UK. Scots living outside Scotland but inside the UK might not get a vote in the referendum, but we have a voice and we care deeply about our country."

Will the Yes camp give a flying Scotsman what Fergie does in his capacity as travelling author? After all, the very fact that Ferguson does not live here should mean his views have less of an impact. Yet politics, and this independence referendum in particular, was never going to be as cool-headed and rational as that. If it was, Sir Sean Connery, the king across the water (several waters in fact) would not have spent all these years functioning as the box office draw of the nationalist camp. But Scotland is hardly a sucker for celebrity politics. Regardless of what the parties might think as they try to gather endorsements from this business person or that actor, Scots are by instinct immune to the razzle-dazzle of shiny endorsements. Someone using their elevated position to impose their views is decidedly un-Scottish, and more liable to provoke irritation than admiration.

Yet when it comes to Sir Sean and Sir Alex, exceptions tend to be made. By virtue of what they have achieved in their careers, Connery and Ferguson are somehow deemed above the fray and worthy of attention. As such, Sir Alex's travels through the UK and Ireland are not just another book tour, and the SNP surely knows it.

The two sirs matter because they speak to - poncey word alert - the narratives of each side, for and against independence. It is essentially the same argument, but with crucial differences here and there. Both men are proud Scots from working-class families. Both, by virtue of hard work and the odd touch of outrageous good fortune, built successful careers in fiercely competitive industries. Both made their names inside and outside Scotland. Both have made a virtue of their heritage.

Yet at the crossroads they separate: Sir Sean for independence and Sir Alex for the Union, the movie star pointing to sunlit uplands, the ever-practical former football manager declaring that the weather where we are is just fine. Which option appeals most to the Scottish head and heart?

That is the other referendum question, not the one that will be on the ballot paper but the one that will determine where the undecideds line up. With months to go, how those ranks of "don't knows" must be haunting the sleep of both camps. So much hope, or fear, being generated by a sizeable few. So much time and money being invested in identification and persuasion. And the outcome uncertain until polling day is over. That's the trouble with don't knows: they are by nature unpredictable.

From today until next September, the undecideds will be as much of an obsession for the new Scottish Secretary, Alistair Carmichael, as they are for the Yes camp. Time is running out for the more laid-back approach to winning hearts and minds, as Michael Moore found out to his cost this week.

Mr Carmichael believes he speaks the undecided's language, telling The Herald: "The case for the head is clear. There is an appeal that we can make to the heart and we have got to go out and do that, and we are not going to leave that part of the pitch to the Nationalists." Mr Carmichael, then, is a head and heart man. But everyone in the Yes camp would likely claim the same, leaving the undecideds to swither further on the vine.

We live in discombobulating times in which the independence referendum is at once a familiar exercise in democracy and an expedition into the unknown. Both sides, encountering so many undecideds, are operating outwith their comfort zones, facing voters looking for signs and wonders alongside hard facts. Strange days indeed, the kind of times when a former football manager punting his autobiography, or a successful Olympics, can send blocks of votes one way or another.

Whether they stay there is another matter. In six months' time the Fergie book and tour could be but a distant memory, with only the paperback and a few ticket stubs on the hall table as reminders.

By then, however, Andy Murray, Wimbledon champion and as proud a Scot as Sir Alex and Sir Sean, might have decided one way or another which side he is backing, and so the wheel of fortune turns again.

Undecideds are unpredictable, remember. Regardless of what turns out to be in Fergie's autobiography, or what he says on tour, nothing beats that last fact for sheer thrills.