Conte's 3-4-3 has lost its fear factor
The Blues have have put together an impressive run of nine wins in nine games but their opponents appear to have worked out the formation that confounded earlier in the season.
Even though Chelsea have now won each of their last nine games, Antonio Conte has a problem to solve - Tottenham, Manchester City and West Brom have all worked out how to stop them in their last three.
Conte's switch to 3-4-3 heralded a phase of invincibility earlier in their nine-match winning run with dominant displays against Manchester United and Everton, as well as six consecutive clean sheets in the Premier League, but against West Brom the manager abandoned his formation as he desperately tried to turn the match.
Diego Costa's stunning goal in the 75th minute killed off Tony Pulis's side at Stamford Bridge but what might be forgotten was that Conte switched his system not once but twice in the second half.
Chelsea could not scrape together a shot on target until the 41st minute as their opponents took the initiative and went very close on several occasions.
The Blues' first switch came as Willian entered the pitch in the 63rd minute, Conte looking to a 4-4-1-1 formation to change things. He then opted for Jose Mourinho's favourite system, the 4-2-3-1, in the 74th minute as Cesc Fabregas came on.
Nemanja Matic looked confused upon the second change as he dropped into a deeper role to accomodate Fabregas but these switches show that Conte is increasingly concerned as he becomes increasingly reliant on the clinical finishing of his striker, rather than prolonged periods of domination.
Chelsea maintained possession but rarely looked threatening until they got their goal. Tottenham, like West Brom, exposed the Blues when they pressed their opponents high up the pitch and tried at every opportunity to prevent their opponents from switching the play.
Mauricio Pochettino's perfect plan was halted by a remarkable Pedro goal, which came against the run of play. Manchester City tried to exploit Chelsea's left side of defence with Kevin De Bruyne and Jesus Navas, making Marcos Alonso and Gary Cahill look very uncomfortable, until they took the lead with a Cahill own goal.
Overloading the left-hand side is one strategy which pays dividends against this Chelsea team. Another is having clever forwards expose Victor Moses's understandable lack of defensive discipline, as Son Heung-Min did for Spurs.
All three of Chelsea's recent opponents aimed to stretch drag their defensive three into wider areas where they are less comfortable, as their side's target men dropped into those spaces.
Conte has used several systems so far this season and might be tempted to pull something new out of his Santa's sack of formations ahead of a busy a Christmas period.
The 3-4-3 is no longer strange, special or difficult to play against but, thanks to Chelsea's mental toughness, they continue to claim all the points.