Something to do with all that increased testosterone giving them an aggressive edge, according to their scientists last week. If the Latin theory is correct, then we can presume only that Gianluca Vialli's men replaced training by re-enacting an orgy scene from Caligula before the annihilation of Feyenoord.
Thirty-seven attempts, on and off target. Even the most sceptical of the Blues brothers at Stamford Bridge on Wednesday night could not have departed unimpressed by the manner in which Chelsea indulged themselves as Vialli choreographed a varied repertoire from his team. They could rarely be accused of predictability and that is what ultimately made it A Night to Remember rather than One Of Those Nights.
Yet, if there was one particularly successful strategy it was the domination of the right flank of the opponents' half. That will be, for the foreseeable future, Dan Petrescu's domain. The Romanian is invariably integral to everything that passes through this bemusing triangle, created together with the defender Albert Ferrer and either Gianfranco Zola or Tore Andre Flo. A defence can easily get lost in its one-touch intricacies, beguiled by the final penetrating through-ball or one of Petrescu's or Ferrer's crosses.
Significantly, it was the all-purpose Petrescu who crossed for Babayaro to arrive late and convert what proved to be the psychologically damaging first goal. It was the Romanian who headed back across goal for Flo to profit with the second after the predatory Babayaro had struck the bar.
Maybe the midfielder will never possess the extravagant poise of a Gustavo Poyet, or tenacity of a Didier Deschamps, but how Kevin Keegan would relish this versatile, goalscoring performer who does not regard his left boot as a slightly irritating fashion accessory. Today, he is almost indispensable; yet, less than a year ago, Vialli was prepared to allow the Romanian international to leave, which says much about the strength of his squad, and perhaps something about the Italian's judgement.
Vialli's predecessor, Ruud Gullit, had also frequently consigned him to the bench. There are foreign players who might have sulked, before departing ungraciously to one of several foreign clubs that coveted him. Instead, the rejection galvanised the veteran of more than 80 Romania appearances - including that one in which he embarrassed his Chelsea team-mate Graeme Le Saux and England in France 98 - into producing his best performances in four years at the club.
He anticipates agreeing a new contract within the year. "I have never been so happy in my life, because I am playing," Petrescu declared. "When I moved from Sheffield Wednesday it was always my intention to finish my career here. That's what I'd like to do. Just over a year ago, I was not happy because I was not playing. I did not want to move and I stayed and I was lucky. The fans sang my name when I was on the bench and that helped me make up my mind."
Petrescu bears more than a passing resemblance to the actor David Duchovny, who plays agent Mulder in The X-Files, a character who is convinced aliens are out there. As one himself - in the immigration sense - the Bucharest- born player is attempting to divest himself of the title. "I am close to getting my British citizenship," explained Petrescu, 32 next month.
"You need to be here five years. It is very difficult for a foreign footballer to find happiness when he leaves his home, but my wife and family [he has a daughter named Chelsea] have settled and enjoy it in London. I want to play for a few more years, maybe until the next World Cup. When I retire I would like to stay here, perhaps coaching, but it is difficult to get a job in football."
Those who protest at the numbers of playing imports will, no doubt, be equally dismayed at the prospect of too many of their number remaining here as coaches and managers. No doubt the League Managers' Association would echo the concerns of their Professional Footballers' Association counterparts. Yet there is surely good sense in encouraging those who enhance our game as elite performers to remain and do so in a tracksuit. From the current Chelsea ranks, it is conceivable that the likes of, say, charismatic and articulate characters such as Zola or Frank Leboeuf have other ideas anyway but, if they decided to stay, their international experience could only benefit the British game.
Just as with the England team, insularity may satisfy the xenophobes and continue a long tradition, but will not necessarily advance the technical and tactical progress of the game in this country. Vialli, of course, is already vindicating Ken Bates' faith in the appointment of an untried Italian manager, though when the man in question might have anticipated wreaths of laurels he appeared slightly perturbed that the post-match inquisition was more about criticism that his team had been over-intricate. He merely responded in that politely studious tone of his, inflected with a hint of sarcasm: "Perhaps we should concentrate on scrappy goals, own goals, goals from long distance. But it's not the way we play."
The Dutch champions are far from the most formidable team which has survived to stage two of the Champions' League, and certainly many light years from the one which once exhibited total football, but the canny Leo Beenhakker, veteran of numerous European campaigns with Real Madrid and Ajax, had his team drilled like an elite defence corps. It required all of Chelsea's guile to dismantle them, as it will when in Rome in nine days' time. "Lazio are still the favourites of the group for me," Petrescu maintained. "But we go there with nothing to lose.
"Milan won the championship last season, but maybe Lazio are the better team, as they are showing in the Champions' League. For us, it will be the toughest game."
But in the Chelsea psyche the threat of Marcelo Salas and his team-mates must not become an unwelcome distraction. It will need resourcefulness of a different kind to unhinge the door of the somewhat more utilitarian visitors, Bradford, today. "We didn't celebrate tonight; it was just three points we won," Petrescu insisted. "We have to concentrate again on Sunday now and make sure we have no excuses afterwards. Bradford are a good team, but Feyenoord maybe are the better team, and we have to play the same. If we beat Bradford, it could start a good run in the Premiership."
They need it desperately. Before yesterday they were languishing 12 points behind the leaders, Manchester United, albeit with two games in hand. That suggests Chelsea will need to win the Champions' League to ensure qualification next season. "Mentally, we are not approaching Premiership teams the same way as European games," Petrescu reflected. "In Europe you have more space to play, more time. The opposition doesn't pressure so much as English teams which are much harder to play against."
As the faithful made their way to the game on Wednesday, a balloon-festooned van conveying Michael Portillo was reminding the voters of Kensington and Chelsea of Thursday's by-election. His victory turned out to be as comfortable as Chelsea's even if, like Stamford Bridge, the turn-out was poor. He can relax. Not so, the footballing Blues, who may find their next opponents made of somewhat sterner stuff.