In experience, there will be nothing much in it. Backs, you might think, have greater powers of survival than forwards, for only the two hookers remain en poste. The true explanation is that in 1990 a great England pack, and a great Scotland back row, were at the height of their powers and were inevitably to be dispersed in the succeeding years.
The Scottish back row then consisted of John Jeffrey, Derek White and Finlay Calder. It is a fair summary to say that they won that match - together with Chalmers (who succeeded with three penalties) and Moore, who insisted on taking tapped penalties in positions from which Simon Hodgkinson could easily have kicked three points.
It is an equally fair summary to say that on Saturday the back row won the match against Wales. Rob Wainwright put in a literally towering performance, and would be challenging Tim Rodber for the No 6 jersey in a Lions XV. Eric Peters scored a marvellous try which will be replayed for months: and no, Ken Logan (another Lions candidate), did not put his foot in touch. As for Iain Morrison, he played the game of a traditional No 7, which is what he is.
There are two things to note about this Scottish back row, in addition to their demonstration that, to be successful in the modern game, you do not have to play three No 8s - even though Wainwright can readily switch to that position.
The first is that they are all products of Cambridge University. So also, of course, is Gavin Hastings. England have three old Blues: Tony Underwood and Andrew from Cambridge, Victor Ubogu from Oxford. Wales and Ireland have one each: respectively Mike Hall from Cambridge, Brendan Mullin from Oxford.
I am not seeking to derive any wider moral from this, but merely drawing attention to the fact that the two most successful sides in the Five Nations' Championship have, between them, seven old Blues, and the two least successful sides, two.
The second thing to note about this back row is that they all play for clubs outside Scotland. So does David Hilton. Indeed, it would be possible to assemble an entire Scottish pack composed of players from outside Scotland: Hilton, Alan Sharp, Burnell, Cronin, Andy Reed, Wainwright, Peters, Morrison. Others would be waiting on the touchline, notably Peter Walton of Northampton and Ian Smith of Gloucester.
Increasingly, Scotland are coming to resemble Jack Charlton's Republic of Ireland football team. They are put together on what might be called the grandmother principle. Wales are unable to trawl the English clubs to such profitable effect. Whether this is because they do not want to, or because the players are simply not there, is difficult to say.
Yet of recent English internationals, Simon Halliday was born in Haverfordwest. Gareth Chilcot and Nigel Redman originated from Cardiff. Dewi Morris, from Crickhowell, is as Welsh as anyone can be. Steve Bates' father comes from Merthyr. Will Carling's father was Sergeant Bill Carling, who played prop for Cardiff. Huw Davies and Stuart Barnes were both eligible to play for Wales but preferred to opt for England.
All these players have qualifications to play for Wales which were at least as good as - or, in some cases, better than - those possessed by Anthony Copsey, Rupert Moon or Hemi Taylor. But for years, years of success but also of arrogance, the Welsh selectors spurned players who appeared for English sides, unless that side happened to be London Welsh.
With that club in the Courage Division Five (South), it is time for the Welsh generally to be less introverted. Ieuan Evans, at any rate, recognises this with his projected move from Llanelli to Harlequins: though if Quins go down to Division Two poor Ieuan will have turned out to be unlucky yet again.