On the Premiership: When Peter Kenyon suggested last August that the winners of this season's Premiership title would come "from an elite group of one", he was stating a fact as bald as his head. If the Chelsea chief executive is asked again this summer, his answer may not be so emphatic.

It has taken 18 months of patient, tentative chipping but cracks are finally beginning to appear in the Chelsea facade. The reigning champions produced another faltering performance against Birmingham on Saturday, scoring none where Liverpool scored seven, and their lead at the top of the table is now down to seven points.

The title should still be theirs, but Chelsea's swagger has gone.

And about time, too. For too long, teams have approached games against Jose Mourinho's side as exercises in damage limitation. They have glanced nervously at the Chelsea team-sheet, mentally totted up the accumulated value of their opponents and hoisted the white flag in abject surrender. Thrashings have been shrugged off; narrow defeats celebrated as moral victories.

Perhaps we have all listened too unquestioningly to Mourinho's pre-match braggadocio. The Portuguese is an arch Machiavellian and acutely aware of the value of an early psychological blow.

He has always maintained games begin as soon as the first question is fired at the pre-match press conference: hence the taunts, boasts and jibes that have become standard fare at his briefings.

Teams have walked out to face Chelsea with Mourinho's words ringing in their ears, but increasingly it appears his bombast is baseless. Chelsea have not suddenly become a bad team but they are not the unstoppable, invulnerable force they looked at the start of the season.

Indeed, they are now being floored by lesser beings - Aston Villa, Middlesbrough, Fulham and now Birmingham, all deeply embedded in the bottom half of the table.

It was Fulham who provided the most compelling case against Chelsea's irresistibility by beating them 1-0 a fortnight ago. Chris Coleman's triumph was secured courtesy of a simple, yet exemplary, tactical ploy that rested on nullifying the influence of Claude Makelele.

The midfielder is Chelsea's weapon of stealth, mopping up behind the offensively minded Frank Lampard and acting as a shield for the back four.

Coleman neutered him by deploying Steed Malbranque in a free role, the Frenchman buzzing menacingly behind two central strikers and dragging Makelele out of position. Chelsea's rhythm was destroyed and the game was Fulham's.

That seismic afternoon hinted at another chink in Chelsea's armour, namely their lack of tactical flexibility. Mourinho is religiously devoted to his 4-3-3 formation, which allows his side width and penetration without sacrificing defensive solidity, but when it fails, he has shown a marked inability to offer a viable alternative.

Against Fulham, Mourinho ripped up his game-plan after just 26 minutes and switched to 4-4-2, to no avail.

Last season, when Chelsea were losing to Newcastle in the FA Cup, his attempt to turn the tide involved three half-time substitutions: Chelsea were subsequently forced to finish the match with nine men after Wayne Bridge broke his ankle and Carlo Cudicini was sent off.

Then, perhaps most embarrassing of all, was Mourinho's attempt to salvage something from their recent Champions League tie with Barcelona. With the Catalans in control and Chelsea devoid of inspiration, the manager's answer was to send poor Robert Huth, the lumbering German defender, up front.

It was a device that smacked of desperation.

So, Chelsea are beatable, but that alone is not enough. The Londoners will remain unperturbed by their occasional glitches so long as their rivals fail to match their consistency, but now the signs are that next season's Premiership will be a genuine contest.

The assault promises to be three-pronged. Liverpool have hovered near excellence this season without ever quite attaining it, their efforts stymied by a lack of attacking punch, but some shrewd transfer dealings this summer should solve that.

Arsenal, meanwhile, continue to flourish. Their performance against Aston Villa on Saturday brimmed with vitality and the fact three of the scorers - Emmanuel Adebayor, Robin van Persie and Vassiriki Diaby - were under 23 indicates the club has a bright future, with or without Thierry Henry.

Then, finally, there is Manchester United. It has taken three years of trying but finally Alex Ferguson appears to have struck upon a winning formula. His side, fired by a resurgent Louis Saha, a chastened Ruud van Nistelrooy, and the dynamic Wayne Rooney, can match any in the world for attacking brio, and while their midfield remains flaky, that problem could soon be rectified with an astute signing or two.

With Mourinho's mystique stripped away and his side's shortcomings currently being laid bare, Ferguson will feel that Chelsea can be overhauled. So will Arsene Wenger and Rafael Benitez.

Next season's title race starts here.