Reports of their demise are not so much exaggerated as invented. That is the party line from Chelsea, proclaimed with a defiance that some of their displays can lack. While it is greeted with scepticism, the ultimate test lies in time. There are reasons to believe Chelsea are in decline, whether the age of their squad or their faltering form of late, but perhaps the greatest factor for believing that the greatest spell is nearing an end is simpler: history.
Put simply, only two English clubs have ever managed to extend excellence without interruption: Manchester United for the past two decades and Liverpool for the two before then. A case could be made for the inclusion of Arsenal, who are on course for a 15th successive top-four finish, but although a six-year wait for silverware might be ended on Sunday, a fallow period of that duration would be unacceptable for Chelsea. But even in marrying transition with damage limitation, Arsene Wenger is a rarity.
When others thought they had a dynasty, their subsequent slide proved they merely had a team. That is a particularly pertinent concern for Chelsea. Since the spine of Petr Cech, John Terry, Frank Lampard and Didier Drogba was formed in 2004, some key components, such as Arjen Robben, Damien Duff, William Gallas, Claude Makelele and Ricardo Carvalho, have been removed and others - Michael Essien, Ashley Cole, Florent Malouda and Nicolas Anelka - added. Yet in style and personnel, it is effectively one team. While the sense of stability has not extended to the dugout, several managers have implemented a similar ethos.
The £75 million investment in Fernando Torres and David Luiz is the latest attempt to extend Chelsea's glory years; the much-hyped youth policy was another. But posterity proves that breaking up a team is hard to do: replacements are often inferior or ill-fitting. Don Revie's Leeds side grew old together, as did Stan Cullis' Wolves. One of the charges that can be levelled against Kenny Dalglish is that, in his first spell at Anfield, he failed to prepare for the future - instead, Graeme Souness steamed in with too much money and too little judgment and discovered Dean Saunders, Mark Walters, Paul Stewart and Julian Dicks could not carry on a tradition of trophies.
Jamie Carragher made a compelling point last year when he argued that it was not Sir Alex Ferguson who knocked Liverpool from their perch but Souness. The warning, should Roman Abramovich choose to heed it, is that managerial changes often account for the fall from grace. Manchester City's finest team was steered off course when Malcolm Allison displaced Joe Mercer, going from sidekick to driver. Revie left Leeds, perhaps unwilling to face the reality that his stalwarts were nearing the end, but the incendiary choice of Brian Clough as his successor backfired. Everton played it safer in 1987, promoting from within by choosing Colin Harvey to carry on from Howard Kendall, but two league titles in three seasons have been followed by none in 23.
Herbert Chapman ensured the end of an era at Huddersfield by decamping for Arsenal, and the combination of his death in 1934 and the advent of World War II five years later stopped dominance becoming a theme at Highbury. It is one of two prime examples of misfortune: the greatest is at Old Trafford. Sir Matt Busby built three great teams, either side of two lulls. The first was caused by ageing, the second by the Munich Air Disaster. Without that, it is possible to imagine the generation of George Best, Brian Kidd and Nobby Stiles seamlessly succeeding the original Busby Babes while Duncan Edwards and Bobby Charlton straddled the eras. It was not to be, however, and United fell as far as 19th place in 1963.
Clough - after his rehabilitation at Nottingham Forest - and Tottenham's Bill Nicholson were other managerial patriarchs to capture silverware in their later years, but only after a dip. Each had two different teams at his respective club but bridging the gap contained difficulties.
The fly-by-night feats of one-time winners are explained by a more equal distribution of talent at the time. At a stage when more money separates top from bottom, the elite are more established. But sustained success has only been achieved twice. The formula is inexact: United have had one manager, Ferguson, whose extraordinary will to win helps explain it; Liverpool had four (Bill Shankly, Bob Paisley, Joe Fagan and Dalglish) with the Boot Room philosophy offering continuity.
The group of players who acquired the collective nickname 'Fergie's Fledglings' remain huge contributors at Old Trafford and, while Anfield's homegrown contingent included such notables as Phil Thompson, Jimmy Case and Sammy Lee, they benefited more from identifying young - sometimes cheap and unknown - players whom they schooled and improved. From Steve Heighway, Ray Clemence and Kevin Keegan through to Alan Hansen, Ian Rush, Bruce Grobbelaar, Ronnie Whelan and Steve Nicol, the list is long and distinguished.
Liverpool were prepared to spend heavily, whether on Dalglish or John Barnes and Peter Beardsley, but did so comparatively infrequently; United, from Gary Pallister, Paul Ince and Roy Keane via Dwight Yorke, Ruud van Nistelrooy, Rio Ferdinand and Juan Sebastian Veron to Wayne Rooney and Dimitar Berbatov, have done so more often.
Yet both could rely on much else besides the chequebook: a winning mentality, an environment where emerging players bloomed, a mix of youth and experience and excellent long-term planning. Despite their considerable prowess, Chelsea tick too few of the boxes and decline could be the consequence.