Their baseball "World Series" is the classic example as it's pretty obvious that if they allowed a team from Leeds to join in, none of the steroid pumped American teams would stand a chance !
I also think whichever team wins the Super Bowl are known as World Champions, but I may be wrong on that one.
Today, over in Leeds as it happens, they've had the Rugby League World Club Challenge. Were there teams from Burkina Faso or Gabon involved ? No. From rugby playing France or Ireland even ? No again.
This match, to find the Rugby League World Champions, is played each year between the champs from England and the champs from Australia. It's sometimes even billed as the clash of the hemispheres, given that Leeds is in the Northern Hemisph....oh you get the point. So not exacly a world challenge then, unless the main challenge is to keep all but 2 of the world's countries from playing. Success then.
And if anyone is bothered, an injury plagued Leeds team battled bravely despite desperate, and ultimately insurmountable, odds (up against huge bronzed Aussies who get lots of fresh air and sunshine for one thing) and were narrowly defeated 28-20. I mean that was soooo close, it was almost a Leeds victory !
If we ever get sunshine in England, we'll be World Champions...of The World.