I am completely convinced that not having to play in Europe is a major factor when it comes to us dominating this season.
I'm only saying this for us though, our squad is small and weak, teams that spent billions on their teams of renowned talent don't really have an excuse for their failures, but a team with a small squad, sure, not playing European competitions is the most important factor out there. Leicester would have done much better without CL this season, I'm sure of it.
Of course, since two teams without Europe are at the top, I expect the debate surrounding this to start soon, but the problem these pundits will go after, will of course be about how tiring Europe is and how frustrating it is to travel to Russia every 3 weeks when playing in EL, rather than how pointless it is to play tons of matches between December and January, and how you don't get a breather in winter.
Because that is another major factor, the amount of home games. People keep wondering why English teams aren't dominant in Europe anymore, well perhaps it would be wise to look at the amount of fixtures that are played on the continent in this winter period for clues. In the age where even referees now admit (Clattenburg interview) that it's getting harder and harder for them to follow the game since it's getting so intense and players are fitter and press more, teams that get that winter break are most likely going to be performing much better in the new calendar year, as well as get back to competing without a long list of injuries.
Just saying.