Chelsea play like Bolton, against decent opposition, they just try and win free kicks round the area and then use their big players to head the ball in or get a knock down. They do this cos they know it's the final 3rd where teams will try and break up there move and they don't have the skill to break down decent teams so they go for cheap goals from free kicks.
Just look at their game against Arsenal, they created nothing from open play, but got 2 cheap goals from set pieces (a bit fortunate Arsenal are crap on set against set pieces), but laughably, Arsenal should have scored 4, so it's not even like their defence is that great. Much the same against Barca, Bayern etc, used the long ball against them and that's where they got their joy.