SCOTTISH football retains such a narrow focus that there will be some who would be quite happy if Celtic and Rangers were simply to ignore the rest of the clubs and play each other 38 times a season - paramedics and police officers presumably not among them.

In the eyes of some Celtic fans the term Old Firm ceased to exist when Rangers went into liquidation in 2012 but that has seemingly not diminished their appetite for this fixture whenever it has rolled around. Each of the four meetings between the teams this season has sold out and there will be precious few empty seats up for grabs when they do it all again in the semi-final of the Scottish Cup in a few weeks, and then again in the league after the split. Some things never change.

Even in Rangers’ diminished state, this remains Scottish football’s flagship fixture. It is our USP, the derby that is said to be known the world over. Celtic and Rangers are still considered two of European football’s leading institutions, even if – in Rangers’ case especially – that is more on historical grounds rather than based on any modern-day allure. Put them together and it is not difficult to see the appeal, even to an English audience who beyond that tend to view Scottish football as if it were something unpleasant stuck to the sole of their shoes.

The paradox, though, is that it may also be the fixture that is holding Scottish football back. For at the heart of any discussion over the future for the game there remains one seemingly immovable caveat: there must be four Old Firm league matches a season.

Sky Sports and BT Sport currently show 60 live SPFL games between them each year but one particular quartet of matches evidently takes precedence over the rest. Following Rangers’ promotion last summer, the return of the Glasgow derby has been welcomed most by Sky who have the rights to show the four league encounters, as well as the forthcoming Scottish Cup tie.

BT, though, want a piece of the action and are thought to be willing to pay for the privilege. A potential bidding war could only help the finances of the clubs involved. The next TV deal, set to start from 2020, will likely be worth substantially more than the £20 million a year being paid currently by the two main broadcasters.

BT are said to be interested in going it alone this time and you can be sure that part of any agreement would be the requirement that the four Old Firm games a season stipulation remains in place. It is, after all, the one spectacle they can market to their viewers in the rest of the country.

That would also have the effect, however, of placing Scottish football over a barrel regarding future changes to its make-up. It would be easier to scale Mount Everest in a dressing gown and slippers than find consensus whenever the thorny topic of SPFL league reconstruction returns to the agenda, but it is not helped by the insistence that the teams must play each other four times each season, largely at the behest of the broadcasters and the league’s two largest clubs.

Scottish football has shown of late that it is not immune to innovation. Both the League Cup and Challenge Cup have been overhauled – the latter perhaps going too far in certain aspects – while a short winter break has been inserted into the calendar to murmurs of approval. The introduction of the Premiership/Championship play-offs a few years back was another long overdue and much-welcomed move.

In terms of the number of clubs in the top division, however, it seems there is less scope for flexibility. One of the general gripes among supporters is that sides playing each other four times – before possible cup meetings – becomes stale after a while. The major rivalries across Europe – Liverpool vs Manchester United, Bayern Munich vs Borussia Dortmund, Inter vs Milan, Real Madrid vs Barcelona – do not seem any less significant because the sides meet only twice rather than four times a year. Scottish football, though, seems determined to continue to buck that trend.

The preference among many fans – as articulated widely around the time of previous debates on the matter - would be to see the top division expand from 12 to a possible 16- or 18-team league. The strength of the Championship this season, as demonstrated by the performances of Hibernian, Dundee United, Morton, Falkirk and others, would suggest it could be done without any noticeable drop-off in quality. Teams would play each other only twice and without the need for a league split that, while undoubtedly adding to the sense of end-of-season excitement, can often deliver an unfair fixture imbalance.

Going down that road, however, would require clubs to sacrifice money for modernisation, finance for freshness. And that may prove the hardest decision of them all.