Liverpool and Manchester United is a peculiar rivalry. It might be "England's biggest game" but it has never truly been England's biggest game.
It is based on history and geography more than being a truly classic sporting rivalry, because England's two most successful clubs have rarely been challenging for the league title at the same time.
These days, while they aren't competing right at the top, the clubs find themselves in roughly the same position. Liverpool go into Sunday's clash at Anfield just three points behind United as both try to recapture their glory days.
For Liverpool, without a league title since 1990, that's become a way of life while, for Manchester United, it's a more sudden development that has come about since Sir Alex Ferguson retired in 2013.
With 38 league titles between them, these clubs don't consider the top four a proper achievement and both are focused on regeneration and working back towards the status of challenger. But which club is better equipped to get there first?
United's form over the past two months of this season has been extremely poor and the lack of excitement in their attacking play is a genuine concern. Nevertheless, if they can improve at that end of the pitch then the overall shape and structure of the side is very good.
The turnover in playing staff at Old Trafford over the past 18 months has been enormous. Therefore, whereas there was briefly a period when several key players were past their best, only Wayne Rooney, Bastian Schweinsteiger, Michael Carrick and Ashley Young are the wrong side of 30. Van Gaal has an extremely young side, packed with players who will steadily improve.
The downside of the turnover is that United find themselves without many genuinely top-class attackers. This season they've depended far too much upon talented youngsters like Memphis Depay (21-years-old) and Anthony Martial (20), both of whom would likely have been gradually eased into the side during previous, more successful campaigns.
Van Gaal's philosophy is partly to blame for the poor attacking performance but it's equally about players, who are not quite good enough for United's side. Traditionally United have had outstanding attackers who can't get in the starting XI but this season, and with Wayne Rooney out of form, they've barely had any at all.
And that is actually a good thing for United's long-term future. If they're a good side with a pretty poor collection of attackers, they should become a great side when they upgrade. Improving your team isn't all about spending money but United are one club that simply needs better footballers.
The side from Old Trafford also boast the second-highest wage bill in the Premier League, which is not something Liverpool can match.
Where Jurgen Klopp's side are in a similar position is in terms of average age. Of their major players, only Martin Skrtel and James Milner are 30 or over and Liverpool also have potential top-class players already in Roberto Firmino, Emre Can and, possibly, Philippe Coutinho.
Their main advantage over United, though, is probably in terms of their manager. While Van Gaal has won more titles in more countries than Klopp, there's a sneaking suspicion that he's actually slightly behind the times.
Klopp is a more modern manager, who has won a major league title in this era and who preaches concepts more suited to football in 2016. He also has the backing of supporters; even at this early stage, there appears a bond between the Anfield crowd and Klopp, which can't be said for the relationship between United fans and Van Gaal.
Liverpool have two problems, however. First, while they have a talented, young squad, it was not built by Klopp and therefore not packed with his type of player. It might take him a couple of transfer windows to properly overhaul the playing staff and even then there's the inevitable "settling in" period for new recruits. That makes a title challenge next season distinctly unlikely.
The other issue is in terms of finances. Put bluntly, Liverpool have only the fifth-highest wage bill in the division and are considerably short of the top four. It's difficult for teams to consistently punch above their weight in this respect.
Nevertheless, there's some good news. The expansion of Anfield -- initially by around 9,000 seats hopefully next season and then by another 5,000 - should significantly boost Liverpool's match day revenue, which is currently around half that which is recouped by Manchester United and Arsenal.
To consistently compete with those clubs over a long-term period, this simply must improve. A significant proportion of these new seats will be commercial, which will do little to improve the atmosphere at Anfield, but will have unquestionable financial benefits.
Football is obsessed with the short-term; this is a world in which the cliche "you're only as good as your last game" is uttered without any irony. But in the longer term, both Manchester United and Liverpool are in good shape to return to winning ways.
It should happen sooner for United, who have everything in place aside from a few individuals, whereas Liverpool's attempts to claw back the gap to the Premier League's bigger clubs will depend upon stadium expansion, increased revenues and astute decision-making.
Ahead of a meeting between the two clubs in December 2014, Gary Neville famously said this fixture would be like "The Dog and Duck against The Red Lion" and it remains to be seen whether -- and when -- Liverpool and Manchester United will get back to the top.
We can be fairly sure, though, that ninth against sixth won't become the norm.