It would be useful to compare with other leagues where home field advantage is significant. I do not have any data but as a football fan I suspect the following variables are important:

- England is an homogeneous country in terms of geography. There is no 40C degree temperature difference between north/south clubs. Playing in weather conditions one is not used to can affect the away team.

- England is also a small country. The away team can arrive at the stadium within the day. Not only it means they are better rested but also home fans cannot bother them at the hotel making noise, throwing fireworks, etc. preventing them from sleeping.

- The FA is not as corrupt. Sure, certain teams can get away with playing dirty, but in general referees will show red card to a home team player, or call out a penalty for the away team.

- Less threatening environment at the stadium, both for the away team players and the referees. Nobody is throwing food, beer or anything at the players during the game, and hooligans will not try to harm the referee if the home team loses.

> England is an homogeneous country in terms of geography. There is no 40C degree temperature difference between north/south clubs. Playing in weather conditions one is not used to can affect the away team

Also pretty flat. No 1000m+ altitude differences. Competing in Colorado suuuucks.