On the Premiership:As a general rule, Arsène Wenger and Alex Ferguson do not conduct post-match pleasantries. The Arsenal manager would doubtless be happy to crack open a bottle of red with his Manchester United counterpart, provided he can use the Scot's head as a corkscrew, while Fergie - who guards his grudges jealously - will never forget or forgive being spattered by jet-propelled pizza in the Old Trafford tunnel some three years ago.
Professors and wizards might mix easily enough in the world of Harry Potter, but in the Premiership they barely look each other in the eye.
If, however, the pair did manage to swallow their mutual loathing and clink a glass or two last night, they might have shared a chuckle over the plight of Jose Mourinho.
The Portuguese has established a reputation as the man of plenty since arriving at Chelsea, blessed with looks, fame and the biggest budget in world football, but the events of the last six months have taught him that all the roubles in Russia cannot buy him what he most wants: control of his football club.
Mourinho's Alpha-male ego would never allow him to admit it, but he craves the totalitarian power afforded Wenger and Ferguson by their boards.
The Frenchman's dominance has been absolute ever since he was briefed with reinventing Arsenal in 1996 and he now supervises everything, from the first team, to the academy, right down to the design of the dressing-rooms at the Emirates stadium. The grass at the club's London Colney training ground is not even trimmed without Wenger's say-so.
Ferguson, meanwhile, is a natural autocrat hewn from the same granite as his old Aberdeen stamping ground. One of the 65-year-old's proudest boasts is that he knows the name of every member of the Manchester United staff, from the pimply academy trainees to the tea ladies, and the passing years have not dulled his authority.
Even Malcolm Glazer, a businessman with a well-deserved reputation for ruthlessness, knew better than to tamper with Ferguson's status when he took control of United in 2005.
Mourinho can only dream of such liberation. Stamford Bridge has become a magnet for meddlers, with the inevitable result that the club's various chains of command have become hopelessly entangled.
The manager might retain the loyalty of his players - with the notable exception of Andriy Shevchenko - but beyond the dressing-room, his power has been dangerously diluted.
It comes to something when Chelsea - who spent £21 million on Shaun Wright-Phillips and £16 million on Jon Mikel Obi - baulk at their manager's request to sign Bolton's Tal Ben Haim for £3 million.
The club's spendthrift methodology might have been untenable in the long term - particularly if Abramovich is to succeed in his aim of balancing the books by 2009 - but quibbling with such a relatively trivial sum can only be interpreted as a deliberate and humiliating snub to the man who has transformed Chelsea from wastrels to winners in two short years.
Mourinho has every right to feel aggrieved, especially when he looks at the unfettered powers afforded the leaders of his title rivals. And yet, increasingly, Wenger and Ferguson must be viewed as relics of a dying age, when managers were football's answer to medieval monarchs, granted divine right by the sporting gods.
This is now the era of the technical director, the shadowy figure who boasts virtually all the powers traditionally entrusted to the manager - signing players, negotiating contracts and bending the ear of the boardroom - but none of the reponsibility.
When the angry mob assembles outside a club's gates, they do not tend to demand the head of the director of football.
The new way is not unworkable, and there are many managers who are happy to let a colleague conduct the often mucky business of transfer dealings and salary settlements. Martin Jol revels in his title of Tottenham's head coach, and he enjoyed a fruitful partnership with Frank Arnesen - currently the cause of so much resentment with Mourinho - before the Dane left for Chelsea. Jol's job satisfaction has not been dented by the subsequent arrival of Damien Comolli.
But one model cannot suit everybody, and Abramovich's decision to forcibly impose a system of power-sharing on Mourinho - perhaps the greatest control freak in the Premiership, and a man with a history of walking away from situations he finds unpalatable - has backfired spectacularly.
It has turned the manager into the most unlikely martyr, Shevchenko into a Ukrainian super-villain and Chelsea into the laughing stock of English football. And if that did not elicit a shared guffaw in the Arsenal manager's office yesterday evening, surely nothing will.