It has been said that fewer London clubs win the League because they have to play so many derbies, a combination that leads to teams sharing points, allowing their northern title rivals to triumph instead.
Jose Mourinho, so far at least, shows little interest in that theory himself or of letting such an idea get to his players. After all, Chelsea thrashed Fulham 4-1 at Craven Cottage last week. On Saturday, the Blues' manager was supposed to be facing another bogey side from the capital, meaning another tough, gritty game.
It turned out to be nothing of the sort. With just four minutes gone, when Damien Duff slipped past Paul Konchesky and slid the ball under Dean Kiely for the opener, you could tell the points were heading west and not south of the Thames.
Memories of the home side's 4-2 win here last Boxing Day against the same opposition certainly receded quicker than you could say John Terry, in part because the central defender then scored twice in three minutes after the interval. With Eidur Gudjohnsen's neat chip from Frank Lampard's pass on the hour, the rout was complete. Terry said: "We owed them one from last year so we needed to pay them back and definitely did that with a great performance all round."
The Blues' style is not to obliterate their opponents with attack after attack. It is a slower death than that. As Alan Curbishley, the Charlton manager, noted: "We've been beaten 4-0 but it doesn't feel like one. If they'd carved us open and battered us with eight or nine chances and Kiely diving all over the place it would feel a lot worse."
Timing was the key here. To score so early in both halves saw Mourinho's men twist a knife into Charlton's side to puncture their hopes, although the hosts did not help themselves. Poor concentration led to Duff's goal, which was simply too easy. The Irishman scored inside the first minute last week, so he took his time on this occasion. Curbishley then complained about Terry's goals from set-pieces and he was right there too. The England international charged in for his first and was unmarked at the far post for the second.
At 1-0 Ricardo Carvalho hit his own post with an attempted clearance, but even if that had gone in it would surely not have changed the outcome, such was Chelsea's ease and Charlton's discomfort, which would have increased when they realised they now have just two wins from their last eight games. Curbishley said he was concerned that his team should start getting points now, as "we don't want to get dragged into something".
Whether Mourinho has fashioned a title-winning team will become a little clearer in just under two weeks, when they go to Highbury and visit the champions, Arsenal. "The pressure is back on Arsenal now," said Terry. "We are just enjoying the experience of being top of the table."
Another derby, that should be just a little closer and more competitive. And any victory there, although unlikely to be by four, would be a notable, not to say potentially League-winning, London derby hat-trick.
Mourinho added: "The objective is to arrive on the last day as champions. We showed people we could cope with being the leaders and this is now the third or fourth week we have been top of the League and I hope we can be there for a long time. For me the pressure is not being top. If you are second you have to win your matches, but when you are top you just have to think about yourself."
Goals: Duff (4) 0-1; Terry (47) 0-2; Terry (50) 0-3; Gudjohnsen (59) 0-4.
Charlton Athletic (4-4-2): Kiely; Young, El Karkouri, Fortune, Konchesky; Thomas (Hreidarsson, 64), Murphy (Euell, 64), Holland, Kishishev (Rommedahl, 64); Bartlett, Johansson. Substitutes not used: Andersen (gk), Jeffers.
Chelsea (4-3-2-1): Cech; Ferreira, Carvalho, Terry, Gallas; Tiago, Makelele, Lampard; Duff (Geremi, 71), Robben (Babayaro, 79); Gudjohnsen (Drogba, 61). Substitutes not used: Cudicini (gk), Smertin.
Referee: M Clattenburg (Tyne and Wear).
Bookings: Chelsea: Terry.
Man of the Match: Terry.