With players at the peak of fitness and apparently expertly drilled, early-season encounters are supposed to be cagey affairs. That theory, however, may have been destroyed by results such as Everton 1 Arsenal 6, Bolton 2 Liverpool 3 and Manchester City 4 Arsenal 2. Not to mention the most recent: West Ham 2 Liverpool 3 and Manchester United 4 Manchester City 3. It means that, at this embryonic stage of the campaign, the Premier League is providing an average of almost three goals per game.
Excelling at entertainment, however, the bare statistics suggest the top-flight clubs are faring rather less well at one vital part of the game: defending. History indicates that the division is often won by the team with the best record in the goals against column. Now, besides the league leaders Chelsea, only the Second City rivals Aston Villa and Birmingham are letting in less than one a game.
And that is an indictment of those expected to challenge: Arsenal, Liverpool and the two Manchester clubs. Chelsea established a record when only conceding 15 goals in the 2004-05 season, Jose Mourinho's first year at Stamford Bridge. As it stands, each of these four expensively-assembled rearguards will have been breached more often by Christmas.
Liverpool's defensive difficulties have attracted the most attention. Set-pieces have been a common denominator in the nine goals conceded, although it is simplistic to attribute all to Rafa Benitez's ever-controversial policy of zonal marking. It had nothing to do with the penalties scored by Aston Villa's Ashley Young and West Ham United's Alessandro Diamanti, or the award of either spot kick. Benoit Assou-Ekotto's first Tottenham goal was a rebound after Tom Huddlestone's free kick bounced off the wall while Tamir Cohen's effort for Bolton followed a punt by goalkeeper Jussi Jaaskelainen from his own half.
Other strikes have brought Benitez's practices into question. Perhaps the most damning goals were the headers of Villa's Curtis Davies and the Hammers' Carlton Cole, both rising highest at the near post from corners. In each case, the man out-jumped was Jamie Carragher. Is that a case of systemic failure, therefore, or of an individual failing to perform his task? Given Benitez's unstinting belief in his methods, he would presumably argue the latter. As he is unlikely to revert to man-to-man marking at dead-ball situations, one solution may be to allocate the pivotal near-post zone to another, whether Martin Skrtel, Steven Gerrard or Dirk Kuyt.
Manchester City may also have a susceptibility to the aerial ball. Perhaps the most avoidable of the six goals they have conceded in their last two games were Darren Fletcher's headed brace. They were the sort of goals that illustrated why Mark Hughes wanted to sign John Terry. Others, however, show why Fabio Capello appears to distrust Micah Richards: the right back was partially culpable for United's first and fourth in the dramatic derby and lost Michael Owen deep into added time.
Set-piece goals are a recurring theme elsewhere, but Manchester United have become accustomed to spectacular strikes. They account for five of the six times Ben Foster has had to remove the ball from his net, with Robbie Blake, Andrei Arshavin, Jermain Defoe and Craig Bellamy (twice) staging a goal of the season contest with a difference. Brilliance has been accompanied by blundering, however: Rio Ferdinand's daft scoop preceded Bellamy's second on Sunday.
That was the third moment Foster may wish to forget. The goalkeeper was at fault for Gareth Barry's goal earlier in the same game and, according to Sir Alex Ferguson, culpable for Arshavin's howitzer.
Fallible keepers are not confined to Old Trafford. Arsenal's Manuel Almunia may have erred for Manchester City's opener, eventually debited to him, at Eastlands. Despite considerable competition, Arsenal appear to have made the most needless individual error in Abou Diaby's bemusing own goal at Old Trafford. Liverpool's Lucas Leiva provided a contender for that tag with his own aberration when he defeated his goalkeeper Jose Reina to give Villa the lead at Anfield.
One of the paradoxes of Arsenal's campaign is that they have conceded eight goals in five games while two of their defenders have been widely acclaimed. Thomas Vermaelen has made an immediate impact and looks an astute use of £10 million while many would argue that William Gallas has benefited from a switch to operate as the right-sided centre back.
Yet their defensive record, and in particular the 4-2 defeat at Manchester City, suggests that responsibility is not confined to the back four. City were allowed to advance with comparative ease, prospering because too flimsy a shield was erected in front of the defence. Arsene Wenger's is a team that, unlike some others, does not always defend from the front, while the significance of holding midfielders may also help explain why, minus Xabi Alonso, Liverpool have conceded more regularly.
Benitez's perfectionism is a reason to believe their defensive record will improve. The increasing familiarity of a new-look Manchester City back four should aid them while the rekindling of the established alliance of Ferdinand, Nemanja Vidic and Edwin van der Sar is likely to benefit Manchester United. With less gruelling fixtures ahead of them, Arsenal, too, have the opportunity to keep clean sheets. But at the moment, video analysis may make for uncomfortable viewing for some of the most vaunted defences in the Premier League.