Whats the best Hockey League? NHL
Whats the best American Football League? NFL
Whats the best basketball League? NBA
Whats the best baseball league? MLB
If a team wins the championship in any of these, they are the best team in the world. Its like a A team saying that the AAAAA that won the state championship cant say they are the best team in the state cause they didnt play every team in lesser leagues. You wont here a MLS team (thats the North American version of the premier league) saying they are the best in the world, cause they arent the top league. The ones listed above, however, are, so they do.