West Ham manager Slaven Bilic believes Chelsea are better than the other title contenders because Chelsea are fitter and have quality up front.
Bilic told Standard Sport: “They were then a good side but better now. So what is their secret? Why are they dominant?
“The answer first is – there is no secret.
“The main thing you notice about Chelsea this season is that they are very fit, they work hard, they are very solid and on top of that, they have that quality up front which is basically making the difference in every game.
“If you compare them with the other title contenders, Chelsea are more solid than Manchester City, Arsenal and Liverpool.
“Most of the games, they are winning not totally the Italian way and at home, they play some very offensive football.
“Look at the way they push up their wing-backs, they are more like wingers. It’s a very demanding position and there is no point in playing that system if the players are not capable of possessing that level of fitness.
“Both of them – Victor Moses and Marcos Alonso – have great stamina and they train hard.
“What makes Chelsea solid is that they never defend with three – it’s always five. The only one who is resting somewhat is Costa and sometimes, Eden Hazard.
“When Chelsea win possession though, Alonso and Moses are right up there and to do that regularly, not now and again, you have to train hard and be almost superheroes.
“The other key points for me are that they have no other distractions and they have no injuries.”