It's a combination of things. Most probably the fact that we have less tournaments overall, and that in smaller countries like The Netherlands, at every tournament, *all* the good players show up, cos it's easy to travel around. That means that every tournament, you're facing at least 2 or 3 other potential Worlds invitees, making your chances at losses bigger, meaning you go 4-2 more often than you go 6-0 even if you're a top player.