Just as, in Arsène Wenger's immortal phrase, everyone thinks they have the prettiest wife at home, so football fans the world over believe theirs is the most passionate derby. In England's second city, where Aston Villa meet Birmingham for a high noon shoot-out today, they are no exception.
The respective managers, Martin O'Neill and Alex McLeish, are not about to play down the rivalry, but they do have the advantage of having experienced the sharp end of what can be described as the unique confrontation that is Celtic versus Rangers. For three-and-a-half seasons they were on opposite sides of Glasgow's great divide. So, while fully aware of all the elements of today's passion play, each can keep it more easily in perspective than those in the stands around them.
"Fantastic occasions, the build-up was intense and I enjoyed them – when we won," O'Neill says of the Old Firm battles. "I remember Walter Smith, although he wasn't there during my time, saying about the derbies that if you won, your first feeling wasn't of euphoria, it was relief. I know what he means. You get a perverse enjoyment out of them, there's no doubt."
After winning his first Old Firm match 6-2, O'Neill established a record between the clubs of seven successive victories, and won 10 of 20 direct confrontations with McLeish, drawing three. His success has continued with Villa, who have won the past five games against Birmingham, including a 1-0 victory at St Andrew's in September, the Blues' nemesis Gabriel Agbonlahor scoring the only goal. More memorably, the last Villa Park confrontation two years ago finished 5-1 in the home side's favour, effectively confirming Birmingham's relegation. Today, they arrive in much better shape, a first season back among the big boys and a chance of the club's highest finish since 1959.
"They've done excellently," O'Neill concedes. "Alex is a very, very good manager, as I experienced in Scotland. If you can come back immediately [from relegation], it's no bad thing and they've got stronger. Stabilising a team in the Premiership is not easy."
Portsmouth's doomed attempt to play in the Europa League next season means Villa will be guaranteed that privilege by finishing at least seventh if they win today. It would have been considered the minimum target for the current campaign, and if fourth place is a bridge too far, the top six should be within reach. Throw in two visits to Wembley in the cups, bringing controversial defeats by Manchester United and Chelsea, and O'Neill believes he was entitled to lambast any suggestion of underachievement, as he did recently when sending out a message about his future that was either confused or carefully couched, according to point of view.
Birmingham, if currently resigned to being second club in the second city, also have an ambitious foreign owner in Carsten Yeung, the colour of whose money supporters will want to see this summer. McLeish was allowed to spend £6 million of it in January, the half spent on Villa's closet Blues fan Craig Gardner proving a better investment than the £3m on Spanish midfielder Michel. Gardner has slotted in well into what has occasionally been an all-British XI at a patriotic working-class club.
Their incentive today, in revenge for the 5-1 thrashing, is to deny the posh neighbours any realistic chance of Champions' League football.