Along with their new goal-line technology, Brazil 2014 officially became FIFA’s ‘World Cup of the Future’ when it was announced that referees would be armed with a special spray with which to mark out the 10-yard line for walls in free-kick situations.

The innovation, officially termed as ‘vanishing foam’, initially received a warm reception from both players and pundits, and even former referees. “It will assist us in getting the players back at a free-kick and, in turn, that gives the attacking team a better opportunity of creating something from that set-piece,” said respected English referee Howard Webb on the spray.

But is Webb, who is on FIFA’s list of possible referees for the World Cup Final in Rio on Sunday, correct with his assertion that the spray has ultimately helped the attacking team taking free-kicks? The spray has ensured walls are made to back up the full 10 yards, but does this really influence the end result? To find out, we analysed every free-kick taken so far at the 2014 World Cup in Brazil, and compared them to the free-kicks at Euro 2012, held in Ukraine and Poland, where the spray was not in use.

Before we look at the effect of the spray, for a start, how many direct shots from free-kicks were there in the last two tournaments? In 31 matches at Euro 2012, there were 46 shots from free-kicks (1.48 per game), in games up to and including the semi-finals at Brazil 2014, there were 103 shots (1.72 per game).

There has been a slight increase in efforts on goal from free-kicks, perhaps as a result of the encouragement given to free-kick takers by the further distance of the wall. But the difference in shots that hit the target is more striking: In 2014, 30.10% of free-kick shots were on target, compared to just 10.87% in 2012.

This dramatic upsurge, of nearly 20%, tells a big part of the story. With the wall further back, takers have more chance maneuvering the ball over or around the obstacle and threatening the goalkeeper. Who knows if we would have enjoyed stunning strikes such as David Luiz’s long-range dipper for Brazil vs Colombia, or Lionel Messi’s accurate up-and-over to put Argentina into the lead vs Nigeria, without referees’ new favourite toy.

Another finding we made warrants a closer examination. You might expect the percentage of free-kicks blocked by the wall to decrease significantly with the advent of the spray, which appears to have resulted in defenders lining up at least 2 yards further back in most cases.

Wrong. There has only been 5.65% drop (34.78% in Euro 2012 to 29.13% at Brazil 2014) in free-kicks hitting the wall since the spray was introduced. Walls are still a problem for takers, if a slightly less challenging one.

But the unavoidable conclusion is that life is becoming harder for teams defending free-kicks, thanks the spray. This is supported by the percentage of free-kick shots that our analysts classed as ‘dangerous’ – 19.57% at Euro 2012 and 33.00% at the 2014 World Cup. Goalkeepers are having to work harder with their line of defence, the wall, forced back.

What are the defensive solutions? Calling more players into the wall to increase its lateral length? But that might leave too many attackers free in the box to receive crosses. Position a defender on the line, with the intention of blocking or heading away a shot beyond the grasp of the keeper? It could be a distraction, as we all know the men with the gloves are determinedly possessive of their own space.

Either way, coaches and technical staff should take heed, because the spray is here to stay.

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