Another new feature of this world cup: it's happening in the autumn during the early part of the European football season, so the players are going to be fresh, fit and in their stride.
This isn't particularly an advantage for national teams as nearly all of the world's best players play in Europe. But it may mean that the quality of play will be very high.
It will be interesting to see how they cope with the switch from cold weather football where people run around a lot, to the heat of Qatar where the ball does the work. It may suit Spain, which has a style of play that works well in hot weather. Brazil also.
Whereas the Northern European pressing game will be exhausting. You'd need a large, young, rotating squad to do it effectively game after game. Five substitutions will make that a bit easier and will suit a squad like England's with strength in depth.