It was probably not the best idea to listen to last Friday's Radio 4 documentary on gender reassignment while driving to Scotstoun to interview Richie Vernon.

 

For, as fascinating as it was, it also served as a reminder that former Scotland No.8 Vernon's decision to move from the pack to the backline would hardly have shocked the rugby establishment any more had he simultaneously announced that he henceforth wished to be known as Dorothy.

It was ever thus in rugby, a sport that takes a more prescriptive view of positional matters than the author of the Kama Sutra ever did. Without getting bogged down in historical detail, the eight/seven split between forwards and backs was pretty much established by the mid 1880s, the only significant change thereafter being the widespread adoption of the 3-4-1 scrum formation in the 1920s.

Sure, the demands of individual positions have changed. I can just about remember watching wingers throwing the ball in at lineouts, while the idea of a full-back having any sort of role in attack only really took hold in the 1960s. The notion that a fly-half should get involved in the grubby business of tackling is also a relatively recent one (and one, for that matter, that a few of them have still to take on board).

Yet it is still remarkable how slavishly rugby follows its own conventions, and how firmly it locks players into one position or another. Now that three front-row replacements are allowed, it has even become unusual to find a prop who can play on both sides of the scrum. Yes, there are still wingers who can play at centre and flankers who can do shifts in the second row - and vice versa - but it is a rare thing indeed to find a player who can step as far out of his comfort zone as Vernon has done.

To his credit, Vernon has set his sights high, confirming that his ambition is not just to do a decent job for Glasgow but to play at centre for Scotland as well as Glasgow. In recent times, the only other Scot to do anything remotely similar was Roland Reid, who won two caps on the wing, but spent much of his career in the back row. Alun Pask and JPR Williams of Wales both played Test rugby as both forwards and backs - albeit in cameo roles - but it is devilishly difficult to recall any other players doing the same.

Looking back, Alex Brewster began his six-match international career for Scotland playing on the flank against England in 1977 and ended it nine years later with three appearances at prop. It was an astonishing transition, although you do wonder whether Brewster suffered too many head knocks along the way, as he subsequently took a controlling interest in Cowdenbeath FC.

Edinburgh current crop of hookers includes Ross Ford and Stuart McInally, both of whom are converted loose forwards. Confusingly, McInally went back to his old job against London Welsh at the weekend, coming on as a back-row replacement (and scoring a try for good measure). It is also worth remembering that Edinburgh winger Tim Visser came to prominence playing in the second row for England schools.

All of which brings us, inevitably, to the question of Sam Burgess, the rugby league superstar who has just signed on at Bath. The 6ft 5in, 18st Burgess is obviously built along the right lines, and he was renowned as one of the most skilful players in the 13-a-side code, but nobody yet seems to have a clear idea which position in union might suit him best.

In three games for Bath - he made two appearances as a replacement before his run-on debut against Montpellier last Friday - Burgess has not exactly set the heather alight, although neither has he done a great deal wrong. Thus far, the west country side have deployed him at inside centre, but the talk around the Recreation Ground ahead of his arrival was that his future might lie in the back row. To his credit, he has also come over as a pretty grounded individual, and one who is keen to learn.

Would that some who have hailed his arrival as the greatest event in the history of the game could show the same level-headedness. The hype around Burgess has set expectations at an absurdly high level, but it has also demonstrated astonishing amnesia. A few who have crossed codes from league to union without a previous background in the 15-a-side game have thrived - Jason Robinson and Sonny Bill Williams spring to mind - but others have not.

At different times, Henry Paul and Iestyn Harris were billed as the saviours of English and Welsh rugby respectively, but both came up short. My gut feeling is that Burgess will be a success, but he needs time to settle in. Quite literally, he needs to know his place.