The Premier League title hasn't been retained in six attempts this decade and every failed defence attracts the same conclusion: the champions got complacent following their success and didn't work hard enough to strengthen their victorious squad.
Manchester United meekly accepted their fate when losing Cristiano Ronaldo and Carlos Tevez after a third straight title in 2008/09. Antonio Valencia, Michael Owen, Gabriel Obertan and Mame Biram Diouf instantly looked like an unsuitable cavalry, and it was no shock when Chelsea dethroned them.
The Blues were similarly inactive once Carlo Ancelotti had delivered a double in his debut campaign, deciding that Ramires and Yossi Benayoun were the only first-team purchases required in a summer in which the likes of Michael Ballack, Joe Cole and Ricardo Carvalho departed.
Sir Alex Ferguson profited on that occasion, yet repeated his 2009 mistakes in 2011, allowing veteran trio John O'Shea, Wes Brown and Owen Hargreaves to follow the retiring Edwin van der Sar and Paul Scholes out, bringing in just Ashley Young and youthful David de Gea and Phil Jones. The situation was so dire that Scholes resurfaced in January.
Helpfully, their usurpers Manchester City had been busy reading the Man United and Chelsea guide on how not to defend a title and unwisely assumed that Richard Wright, Matija Nastastic, Maicon, Javi Garcia, Jack Rodwell and Scott Sinclair would see them over the line. Where are they now?
The summer of 2013 saw the Red Devils make the ultimate post-triumph bungle, ruling that even though they had lost Ferguson and hired top-four-side novice David Moyes as his successor, all he needed was for Marouane Fellaini to be brought with him from Everton on deadline day. It is easy to forget in dismissing Moyes as a huge flop how little he was allowed to put an imprint on the squad.
Six years of inept celebratory spending was completed by Man City in 2014. To be fair to them, they did a reasonable amount of business both numbers-wise and in terms of expense, but the likes of Willy Caballero, Bacary Sagna and Fernando had hardly any impact.
Despite the three most impressive clubs in the country this decade all falling into an identical trap, this year was supposed to be different. Surely Jose Mourinho, a coach who retained titles at Porto, Chelsea and Inter and is admired as one of sport's greatest ever detail men, wouldn't be fooled?
However, while Man United have signed four probable starters, Man City have broken the transfer record for an Englishman, Arsenal have taken a four-time Chelsea title winner and even Liverpool have made some attention-grabbing moves, the champions have done next to nothing.
Their only senior additions have been Asmir Begovic and Radamel Falcao (on loan) and they appear to have been recruited to replace Petr Cech and Didier Drogba on the Blues' bench.
Chelsea remain 2.77/4 favourites regardless, but if they don't liven up soon then serious notice will have to be paid to the prices of their competitors, with Man City at 3.953/1, Arsenal at 5.69/2 and Man United the most alluring of all at 6.411/2.