Sometimes, insight arrives when you’re least expecting it. I didn’t need to watch Shane Warne threaten to beat Gloucestershire all by himself in a C&G Trophy match for Hampshire at Bristol a few years ago to know that he was a world-class leg-spinner. But what I learned that day – thanks to a quirk in the positioning of the press box – was just how preternaturally persuasive he actually was.

The media’s vantage point at Nevil Road is, depending on the bowler’s end, at wide third man or cow corner for the right-hander, a view that provides an unusually acute sense of just how far forward the batsman is getting. Well, they were getting very far forward indeed to Warne, who kept hitting them on the front pad and kept winning lbw appeals – three of them, according to Wisden. Few spinners would have bothered even to appeal; even fewer would have had their shouts upheld. But part of Warne’s secret was his sheer chutzpah. And judging by his performance yesterday at Australia House, where he was promoting a new book, he retains that quality in spades.

Forget, for a moment, his pronouncement that Australia will “wipe the floor” with England next summer unless KP’s boys start winning Tests other than dead ones. Forget the mischievous claim that Michael Vaughan really is England’s best No3. Forget the predictable dig at Ian Bell, Warne’s very own Shermanator. Forget the accusation that South Africa only really have two batsmen. What really impressed was his ability to say, with the straightest of faces, that Australia are actually getting better.

Now, Warne had a book to publicise, and it is not exactly a revelation that outlandish claims can beguile hacks with space to fill. But he really seemed to believe that a side lacking Glenn McGrath, Adam Gilchrist, Justin Langer and Warne himself was on the up.

Let’s put this into perspective. In the early hours of tomorrow morning, Australia begin a four-Test series in India without a decent spin bowler. Even Warne had to concede on Monday that it was the current team’s one missing ingredient, but he did it in a way that suggested he was shrugging off the absence of a violinist in an orchestra. The choice boils down to Cameron White, whose leg-spin has never lived up to its youthful promise, and Jason Krejza, whose already tentative claims to representing the world champions were further undermined by match figures of 31-2-199-0 against a President’s XI in Hyderabad last week.

Much has been made of the fact that Australia’s 2-1 victory in India four years ago revolved around the efforts of Jason Gillespie, McGrath and Michael Kasprowicz. Fair enough. But that interpretation ignores the input of Michael Clarke’s slow round-armers (six wickets at 2.16, although admittedly in the one game Australia lost), Nathan Hauritz’s off-breaks (five at 20) and Warne’s leggies (14 at 30). If Australia’s spinners claim 25 wickets between them this time, they will have surpassed all expectations. Perhaps even Warne’s.

India’s top five – even with Sourav Ganguly bidding farewell at the end of the series, Rahul Dravid in danger of fading away and Sachin Tendulkar on the verge of Brian Lara’s world record and, who knows, maybe fulfilment – should have a field day. Virender Sehwag may fare even better than that, providing he can see off Stuart Clark and Brett Lee. But England fans looking to read the runes ahead of next summer should keep their glee under wraps a while longer.

First, there is no Andrew Symonds, who is paying the price for a fishing trip and other misdemeanours besides. His off-breaks and general competitiveness are more than handy in an emergency. Second, there is no Bryce McGain, the 36-year-old leg-spinner branded yesterday by Warne as Australia’s best slow bowler. In part, it says a lot about Australia’s desperation that a bloke with 19 first-class matches to his name should be worthy of the accolade. But Warne pointed out that McGain’s late arrival in first-class cricket has at least spared his shoulder the wear and tear common to most ageing leggies. McGain could yet wreak terrible deeds on England next summer. Well, Warne probably reckons he can anyway…

Lawrence Booth writes on cricket for the Guardian. His third book, Cricket, Lovely Cricket? An Addict’s Guide to the World’s Most Exasperating Game is out now published by Yellow Jersey