Liverpool's improvement since last season has been down primarily to good organisation, and it's obvious that as long as United and Arsenal continue to struggle at the back, neither club will be able to compete with Chelsea's highly-efficient brand of defence and counter-attack over the course of a championship season.

What you will see with Chelsea and Liverpool today is more evidence of pragmatism over idealism, whereas both Alex Ferguson and Arsene Wenger have always believed in an open, attackminded approach. Only on rare occasions has either manager indicated that he might actually fear the opposition, and that he's going to adjust his team accordingly.

In contrast, Jose Mourinho invariably pays attention to how the other side plays, and frequently makes tactical switches in response to what he sees unfolding on the pitch. The premium he places on defence was evident during Porto's Uefa Cup final against Celtic, and later in the Champions League against Manchester United.

His basic philosophy at Chelsea hasn't changed one bit, it's just that now he has more quality players at his disposal.

Equally, Rafael Benitez showed in last year's Champions League semifinal victory over Chelsea how success in a specific game could be achieved by detailed attention to the opposition's strengths and weaknesses. Both managers have proved themselves by winning Europe's major club competition, and both have done it by getting the balance right from back to front, and not the other way around.

In the youth set-up at Arsenal, we have also slightly altered our approach to developing young players over the last couple of years.

While the emphasis is still on skill and technique, we've certainly upped the ante regarding what you might term the less attractive side of the game.

We want to make the players tougher, we want to make them harder to beat, and if they turn out to be technical, physical and disciplined, we feel that at best, they'll have an opportunity to break into the Arsenal team, and at worst, to make a very good living from football.

While there has been some criticism of Mourinho's cautious approach, I think some people seem to have forgotten that Chelsea have scored more goals than anyone in the Premiership this season.

Chelsea start by being solid at the back, but if they go a goal in front, they can go on and score four on the counter because the other team has to come out and attack them.

It's not that United and Arsenal haven't been scoring goals, it's that their confidence has been undermined by conceding too many, and if both clubs are going to bridge the gap with Chelsea, then they have to address their defensive problems in the transfer market this summer.

Injuries have been a factor, but it has been shown that top teams often define themselves by how they cope when key players are missing. You can make allowances for United, but the truth is that Ferguson has still not been able to address the obvious frailty in the centre of his defence.

If at the outset he bought Rio Ferdinand as a leader, as someone he could build his defence around, then it was a bad decision.

Ferdinand has never been a leader, and he has never had that defender's instinct of not giving an inch, of getting his body in the way of a shot, and of making sure not to concede anything.

He's an excellent playmaker in defence, but he needs a commanding centre-back alongside him, and Ferguson's attempts to team him up with Wes Brown, Mikael Silvestre and John O'Shea simply haven't worked, and the proof of that has come with the recent signing of the Serbian Nemanja Vidic.

Arsenal should have a more solid look about them with the return of Ashley Cole and Kolo Toure for the Champions League game against Real Madrid in just over a fortnight's time, but the club's defensive difficulties of late have been compounded by Sol Campbell's loss of form and a possible season-ending injury to Lauren.

Campbell has been below his best for more than a year now, and while his situation is different to Ferdinand's, the bottom line is that if a team's key defender is struggling, then the rest of the back four is likely to struggle. Contrast the fortunes of both Campbell and Ferdinand with John Terry's relentless consistency, and you have another clue to Chelsea's success.

At their peak under Ferguson and Wenger, United and Arsenal won so often with style, but now Mourinho and Benitez have shown that success can be achieved another way.

They're more concerned with substance, and for the moment, it appears to be working.