Spain's spectacular form since the last World Cup may have been the reason it entered this tournament as one of the favourites, but it is its on-field discipline which is one of the chief reasons why it finds itself in the quarter finals of the World Cup.
While much of the attention at the tournament has been on the performance of the referees, the men in the middle have had little to worry about with Vincente Del Bosque's team, which has proven clearly the best behaved of any of the 32.
When Xabi Alonso picked up a caution in the second half of the second round win over Portugal in Cape Town, he became the first Spanish player in 344 minutes to pick up a booking at this tournament. When you consider that their opponents have picked up 12 cards, including two send offs in their four games to date, you start to see where Spain is getting its advantage.
At the same stage of the 2006 tournament, Spain had picked up six bookings, while in 2002 it had picked up five. Interestingly, when you consider Australia has had three red cards in its past four World Cup games, Spain hasn’t had a player sent off in a World Cup since 1994.
The cumulative effect of having so few cautions at this stage of the tournament, is that Del Bosque knows that Alonso is the only player who can miss a possible semi-final by picking up another booking against Paraguay.
Adding to the sense that this Spanish side is keeping its cool is the fact it has conceded just 43 fouls for the tournament, an average of just over 10 per game, bettered only by Germany of those teams to make it through to the second round. The differential between free kicks conceded and free kicks received is a whopping 31.
It's not as if Spain has needed the rub of the green from the referees. With the exception of its opening match failure against Switzerland, it has dominated its opposition and while it only eclipsed Portugal 1-0, it never seriously looked like losing the match.
As well as discipline, Spain has plenty of depth. The quality of players it had on the bench against Portugal beggars belief and Del Bosque has certainly not overused or overtaxed his players up until this stage of the tournament.
The draw has opened up well and Paraguay, in a World Cup quarter final for the first time, should prove a relatively straight forward assignment. While the South Americans have proven hard to break down, they have also found it difficult to score, managing just three goals in four games, two of those came in 90 minutes against Slovakia.
None of the Paraguayan strikers has hit the back of the net and given the fact Spain has conceded just two goals in 360 minutes of football in South Africa, a semi-final spot against either Argentina or Germany beckons. A win in that match and you would think Spain's long wait for a World Cup title could be over.