On 24 February 2008 Tottenham came from behind to beat Chelsea 2-1 in the League Cup final. Since then, they have sacked Juande Ramos, enjoyed a period of Gareth Bale-driven excitement under Harry Redknapp, taken significant missteps with André Villas-Boas and Tim Sherwood, and then found in Mauricio Pochettino a bright young manager under whom they have made progress in each of the past four seasons. But in that decade, they have won nothing.

Since then, Chelsea have made 11 managerial changes. They have employed Guus Hiddink (twice) and Rafael Benítez as interim managers. They appointed Roberto Di Matteo on a short-term deal but then he won the Champions League and had to be given a longer-term contract that was terminated three months into the following season. They have also sacked Carlo Ancelotti and José Mourinho within a year of winning a league title and look likely to do something similar with Antonio Conte. And yet in that decade, they have won three Premier League titles, three FA Cups, a League Cup, the Champions League and the Europa League.

You don’t have to be Harry Lime sitting on the Prater wheel to start wondering whether a little chaos may not somehow be beneficial.

Causation, though, is not correlation and the truth is surely rather that Tottenham, for all the care of their recent planning, for all the promise and the expectation surrounding the new stadium – complaints about the structure of ticket pricing notwithstanding – are running up against a familiar London problem: that whatever resources you may have managed to scrape together, unless you are one of the mega-rich, you would have been better off spending it 15 years ago.

Chelsea, for all the errors of judgments in the hiring and firing of managers since Mourinho’s first spell, have always been insulated by the initial splurge they embarked on after Roman Abramovich bought the club in 2003.

That is the nature of super clubs: they are, effectively, too big to fail. No matter how badly they sign players or appoint managers, the resources will always be there to bail them out. It may be the Premier League retains an element of jeopardy missing in other European leagues – the prospect of Barcelona or Bayern Munich slipping to 10th, as Chelsea did in 2016, is all but unthinkable. Equally, the consequences of failure are not what they were in, say, 1974 when Manchester United were relegated six years after winning the European Cup, or in 1982, when a Leeds side who had dominated the late 60s and early 70s, were relegated seven years after playing in a European Cup final.

Tottenham’s Jonathan Woodgate (right) heads the winner past Petr Cech in extra time of the 2008 League Cup final against Chelsea. Photograph: Glyn Kirk/AFP/Getty Images

It’s even arguable the nature of English football, with a putative big six, means there cannot be an English superclub, or at least that English superclubs are not as super as those of other leading leagues. With effectively six sides scrapping for four Champions League spots there is no guarantee of picking up the European bonus each year, no self-perpetuating cycle to keep them at the top. Plus, the Premier League is wealthier than the other leagues, the gap between richest and poorest not so great: there is further to fall.

And that is why Sunday is so vital. It takes a lot for the elite to be shifted. It requires the hundreds of millions Manchester City have invested or the decade-long stagnation Arsenal have endured. As a host of clubs with a variety of stories – from Leeds to Everton to Aston Villa to Leicester can attest – a season or two of positive results and investment is not sufficient. Becoming a member of the top table requires sustained and sustainable investment, ideally coupled with the decline of a member of the existing elite.

Tottenham, so far, have invested relatively little in players since Pochettino took over: only around £33m net. Their spending, rather, has been on their stadium. Pochettino’s capacity to get the best out of young players has ensured a greater return on their investment than they could have expected. A sense endures that the project could spin apart at any moment, as players seek the greater riches available elsewhere, and yet they have already surpassed Arsenal, with whatever financial advantage the new stadium gives them to come.

If they end 28 years of failure at Stamford Bridge and win on Sunday, Spurs will move eight points clear of Chelsea with seven games remaining, which would go a long way to securing their Champions League participation next season and keeping Chelsea out. That would be two seasons out of the last three in which Chelsea had failed to qualify for the Champions League.

Abramovich can afford that but the question is whether he wants to. There has been a notable retrenchment at Chelsea, a source of huge frustration for Conte and Mourinho before him. In the past four years, their net spend is roughly double Tottenham’s but the squad (or at least those who have not been loaned out) have looked short for a couple of seasons and are beginning to appear ragged.

Without the lure of Champions League football, without investment, the chaos that has characterised the past decade at Chelsea may be about to overwhelm them. It seems to have come on suddenly but by Sunday night Tottenham, ephemeral as this incarnation may seem, could find themselves the indisputable top side in London.