England's Walter Matthau and Jack Lemmon

Chilli and cucumber. Fidgeter and twiddler. Rebel and conformist. Nature and nurture. Force and timing. Untempered steel and unruffled silk. Player and gent. Big ego and little ego. For Walter Matthau and Jack Lemmon read Big Bad Kev and Good Boy Ian, odd couple incarnate.

Pietersen and Bell. Bell and Pietersen. Either way, for all their blatant chalk-and-cheesiness, here is a duet as melodious in deed as in sound. They even share a mantra. "Watch me! Watch me!" they both insist - albeit one rather more noisily than the other.

In vast contrast to The Oval in 2011, where they ensured a whitewash by ravaging India for 350 off 79 overs - the most swaggeringly substantial middle-order partnership for England since Denis Compton and Bill Edrich ransacked South Africa for 370 at Lord's in 1947 - their role this summer has been that of bacon-savers. That purple passage in the middle session at Old Trafford went a mighty long way towards sealing the hosts' first re-retention of the Ashes since 1981. On Sunday they became the 30th couple in Test annals to post ten century stands, dispelling the looming clouds of a three-day defeat and restoring the scent of victory to English nostrils.

They had shared eight previous century stands before that Saturday in Manchester, but their 50th Test liaison, it felt, was the first to find them as a true partnership of equals. One slice of tit-for-tatting will remain tattooed on the hard drive. Pietersen lofted Nathan Lyon over mid-off, long-off and perimeter ad; uncowed, Bell followed suit in the offspinner's next over: a replica in direction, trajectory and even distance. If Pietersen's blow exuded dismissive power, Bell's riposte oozed disdainful ease. A Lyon outroared, not once but twice.

Seven of those 100-plus alliances have come since the start of December 2010: of the three-figure stands for wickets three, four, five and six in all Tests during that span, Bell and Pietersen lead all comers, having just nudged ahead of two expert mickey-taking Michaels, Clarke and Hussey. Unlike that groovesome twosome, they have power to add. Bell captured the bowlers' dilemma on Sunday night: "It does help us that we've got different strengths. I'm more of an off-side player, cutting and driving. He's more leg-side. It means that we hit similar balls to different areas." Double the breadth, double the headaches.

That stand in Mancunia, perhaps significantly, marked just the third time in those weighty co-productions that Good Boy Ian had outscored His Big Bad Boldness. Here was further evidence of the sea change so visible ever since the former began leading off the innings in ODIs. In that format, six of Bell's eight scores of 50-plus since June 2012 have been achieved when KP has been elsewhere, and he has comfortably outscored him when he hasn't: how he appears to relish those days when it is his shoulders that bear expectation's load. When they share the stage now, we can savour the tang of competition.

Fifty-six Test duets have chalked up eight or more century alliances, of whom 20 have registered more than ten, a roll of honour headed by Rahul Dravid and Sachin Tendulkar (20), Gordon Greenidge and Desmond Haynes (16), Matthew Hayden and Ricky Ponting (ditto), Jack Hobbs and Herbert Sutcliffe (15) and Mahela Jayawardene and Kumar Sangakkara (ditto). For productivity, Dravid and Tendulkar are out on their own, aggregating 6920 to the 6482 amassed by Greenidge and Haynes - whose 148 partnerships make them the most durable dynamic duo - and the 6081 tallied by Hayden and Justin Langer, who actually averaged slightly more (51.53) than the first two pairs.

That sturdy firm of Australian southpaws, though, is still a couple of streets behind the most reliable pairings, among whom the brand leaders may surprise non-Lahorians and non-Karachiites. While Hobbs and Sutcliffe (87.86), Langer and Ponting (82.16), Mohammad Yousuf and Younis Khan (78.42) and Javed Miandad and Mudassar Nazar (75.60) all averaged upwards of 75, none can match Miandad and Shoaib Mohammad's staggering 91.82.

Fancy a couple more pub-quiz teasers? Your starter for ten: how many three-figure stands were co-authored by Len Hutton and Cyril Washbrook, widely hailed as England's best opening pair between Hobbs and Sutcliffe and Geoff Boycott and John Edrich? Eight in 53 innings: an inferior rate to Graham Gooch and Mike Atherton, whose mettle was tested rather more searchingly. In terms of new-ball nuisances, while Hutton and Washbrook had to contend with Ray Lindwall, Keith Miller and not a lot else, Gooch and Atherton doubled as a coconut-shy, being obliged to contend with Messrs Ambrose, Marshall, Walsh, Hadlee, Wasim, Waqar, Donald and McGrath, albeit at varying stages of their luminescent careers.

Now, for a 20-point bonus, how many of those leading 56 batting firms featured Don Bradman, Garry Sobers and Viv Richards? None. Why? Opportunity had a plenty to do with it (especially since Sobers batted at No. 6 during the second half of his career), but so, one can only surmise, did that propensity to cow partners into awestruck timidity. Bradman's most fruitful relationship was with Bill Woodfull (seven century stands in 22 liaisons), Richards' with Greenidge (seven in 38), Sobers' with Rohan Kanhai (six in 34).

Charlie Davis, that tireless buster of received wisdom and fierce defender of hard numerical fact, has done some industrious digging here. Bradman, whose 35 three-figure liaisons in 80 innings averaged an astonishing 204 (every single one of his first ten were worth in excess of 150), was virtually always the domineering senior partner. In century stands in Ashes Tests, despite receiving less than half the strike, he acquired just over 60% of the runs off the bat. His strike rate of 65 runs per 100 balls utterly overshadowed his partners, whose collective mean was just 41. Not until more than 60% of his international career had elapsed, when Bill Brown had the unmitigated gall to make 91 out of 172 at Trent Bridge in 1938, did anyone outscore the Don in a major partnership.

Adept as they are at ignoring context and artistic impression, the harsh facts of statistical life can be horribly sobering. For a fiftysomething Pom, it was faintly depressing to discover that Colin Cowdrey and Tom Graveney, boyhood icons and the most elegant of double acts, averaged a smidge over 33 in their two dozen duets. Still more disappointing was the realisation that, thanks to the selectors' less than immaculate judgement, Graveney and Ted Dexter - in terms of aesthetics the Belly and KP of the late 1950s to mid-1960s - teamed up on just four occasions. David Gower and Ian Botham, their 1980s equivalents, did so 37 times but averaged a nostalgia-incinerating 37. Just once did they add 100 in a winning cause, in Brisbane in 1986, when the former's lack of touch was so painfully palpable, his 51 was almost certainly the most torturous of his 57 Test scores of 50-plus.

While Pietersen's Test duets with Alastair Cook and even Paul Collingwood have been more productive, on average, than those with Bell, this observer can offer no higher praise than to state that, at their united best, they stir memories of The Oval 1970, of an afternoon when Sobers and Graeme Pollock, the batting colossi of that distant era, did the serenading.

The circumstances could scarcely have differed more. Not only was the series already won; in joining forces for the Rest of the World, Barbadian and South African put on a show uncommemorated, scandalously, by the official records. For two hours on a sunkissed Friday afternoon, nonetheless, the best left-handers Bradman ever saw served up a connoisseur's delight, adding 135 in the most commanding, irresistible and delicious manner imaginable. All painterly flourish and feline grace, Sobers contributed the lion's share, pulling Pollock out of his summer-long torpor. Such was the latter's power, one straight drive off Peter Lever clipped the non-striker's stumps and still whistled for four. In a world riven by racial inequality and cursed by apartheid, here were ebony and ivory in perfect harmony.

If that canvas was the handiwork of technical maestros, a marriage of Rembrandt and Michelangelo, it does not seem that big a stretch to liken Big Bad Kev and Good Boy Ian, at their harmonic best, to some celestial fusion of Miles Davis and Tchaikovsky: extemporising innovator and graceful classicist. May those Kennington gasholders witness an encore to treasure.