Glancing at the English Premier League tables the other day, I noticed a strange thing: The top four teams have combined for just one home loss, in 55 games. Yet on the road, the quartet (Manchester United, Chelsea, Liverpool, and Arsenal) have combined for 17 losses in 54 games. In fact, not a single team in the league has a better record away from home than at home, and only the four teams slated for relegation have lost more games at home than they've won. Home-field advantage exists in every sport, but nowhere near this pronounced. What's going on?

In Italy the top four teams have seven home losses, 10 away. In Spain, it's 5 and 17. And in Germany, 8 and 13. All three leagues have at least one team with a better record on the road than at home. Let's look at the 2005/2006 numbers: England (4 home losses, 23 road losses among the top four teams) was again the home-friendlest of the other three top soccer leagues [Italy (8, 23); Germany (9, 13); Spain (10, 23)].

In the big-three US pro sports leagues, the effect is nowhere near as pronounced. The NBA's top four teams, all in the west, have 23 combined losses at home, and 35 on the road. In the NFL, we'll take the top five, because New England and Indianapolis each have identical 12-4 records, fourth-best in the league. They combined for six losses at home, and 10 on the road. In Major League Baseball, the top four combined for a .617 winning percentage at home, .571 on the road.

But back to that original question: What's going on in England? An article in the Times of London last June said that home teams tend to attack more than visitors, leading to more free kicks and more goals—37.29% more than their opponents. Then there's the referee effect: Researchers in 2005 concluded that there's a home bias that can't be explained by other factors. But why are these factors more pronounced in the Premiership? It remains something of a mystery.