The soccer played at World Cups is unique so with that in mind, here are five ways in which the game in Brazil will differ from club competition:
1. More defending
At the last two World Cups, the average game produced only 2.3 goals per game. That's about half a goal less than the average in Europe's four biggest club leagues. In fact, a typical World Cup probably causes more deaths than goals, even though the tournament invariably involves some teams -- like Saudi Arabia or Togo -- who are out of their class and ripe for a good hammering.
World Cups are simply very defensive. The lesser teams tend to mass in front of their own goals, aiming to avoid humiliation. That's why it's generally smart to turn on the TV only once the first round is safely over.
In club soccer, a different set of incentives operates. More games began to be televised live from the early 1990s, and most big clubs now try to please viewers by attacking. Jose Mourinho is widely considered the most defensive coach in top-level club soccer, yet even his Real Madrid side scored nearly three goals per game last year.
Even smaller clubs tend to play relatively open soccer because in a 38-game league season, losing isn't the end of the world. But in a World Cup, losing is the end of the world.
2. One great player can decide a World Cup
With defenses this tight, it can take a genius to unlock them. Diego Maradona won the World Cup for Argentina almost single-handedly in 1986 just as Zinedine Zidane carried France to the final in 2006. Superstars matter even more on this stage than in league soccer.
Lionel Messi for Argentina, Neymar for Brazil and Cristiano Ronaldo for Portugal will have lesser teammates at the World Cup than they do at their clubs, which makes their personal roles all the more important.
The prime challenge for their countries is how to get these geniuses to produce -- a challenge flunked by Maradona in 2010, when as Argentina's coach he devised a system that had Messi getting possession on the halfway line with nine opponents to beat.
3. Simpler systems
A coach at a World Cup has far less time to drill his players in a system of play than does a club coach. That means he can't go for anything complex -- unless, like Spain's coach Vicente del Bosque, he draws the bulk of his starters from a single club (in Spain's case, Barcelona) where they already play the same complex system together.
Most coaches will opt for simplicity. Holland's manager Louis van Gaal says he'll probably only get all his players together a week before they fly to Brazil. For that reason, he says, he'll have to play with a defensive rather than an offensive central midfielder. "I just don’t have the time to mould them into the old Ajax system, 3-4-3 with a real number 10," he says. "You can't do that in a week. That style of play is just too difficult. The balancing of the relative positions is too precise."
In the past, certain national teams could train together for months before a World Cup, as South Korea did in 2002. That doesn't happen anymore. Now, Belgium's coach Marc Wilmots says he tries to give his players the same roles they have at their clubs: "The clubs are doing all the work and I just carry it on. The national team doesn't make any player better."
In short, don't expect tactical innovations at the World Cup. There just isn't time.
4. Microscopic study of opponents
National coaches have little time to school their players in a system, but ample time to analyze the opposition. Imagine the daily life of a coach going to the World Cup. Starting from the draw in December 2013, he and his data analysts (a growing tribe in soccer) have six months to identify the tiniest flaws in his first-round opponents. Club coaches also study opponents, but much more hurriedly. In a 60-game season, the messages they can give their players are briefer.
That makes international soccer rather like a chess game. Before Germany versus Holland at Euro 2012, the German data analysts crunched the numbers on their opponents and spotted a key fact: the Dutch defenders often strayed too far apart. The secret code book for the German national team lays down that the ideal distance between defenders in a back four is eight meters, while the Dutch were regularly leaving larger gaps. In the game in Kharkiv, Ukraine, Germany located those gaps and won 2-1.
5. A battle against tiredness
Players from the exhausting English Premier League, in particular, will arrive at the World Cup wrung out by the club season. (Remember how Premier League stalwarts like Wayne Rooney, Robin van Persie and Fernando Torres flopped in 2010?)
The teams that get to the final will have to play seven games in just over a month. That means it's almost impossible for any country at the World Cup to play at the tempo of a leading club team like Bayern Munich, where it is practically obligatory for a player to sprint the moment he passes.
The Brazilian climate -- especially in the northern cities, and in Manaús in the Amazon -- will sap players too. It's no coincidence that the traditional Brazilian game is stop-start. If you try to go 100 miles an hour in that weather, you'll end up in hospital.
There are two ways for teams to deal with the problem of exhaustion. Either they must lead the sport in scientific preparation and fitness, as Jürgen Klinsmann's Germany did in 2006 (and as his Team USA may this time). Or teams can pace themselves, slowing the game down and then speeding it up when required.
The masters of this are the Italians, who like to strike in the final minutes when the other team is fading. But teams that try to play at top pace from kickoff -- as England traditionally does -- will find themselves fading like a cheap battery.