(REUTERS/Dominic Ebenbichler)

In one of two traumatic last-minute World Cup goals this weekend, Argentina’s Lionel Messi hit an incredible strike from outside the box and wide to beat Iran. The goal prevented Iran from earning a deserved upset draw, and it raised the question of a penalty call.

Earlier in the second half, Iran winger Ashkan Dejagah chased down the long ball at the top right corner of Argentina’s penalty box. Right back Pablo Zabaleta put in a foolish challenge, even though Dejagah’s momentum was carrying him away from goal. Zabaleta got a foot to the ball but also slashed hard across Dejagah’s ankles. The referee signaled no call, and Zabaleta’s risky, though arguably legal tackle went unpunished.


But this is not about questionable refereeing decisions. Instead, I want to ask a question. Let’s say that Zabaleta truly did commit a foul. If it gets called, that’s a penalty and a roughly four-in-five chance of an Iranian goal. If Dejagah had been allowed to collect the ball, his run would have taken him well wide of the goal. Did Zabaleta deny a chance worth anywhere near 0.8 goals when he stuck his leg out?

Another example would be Daley Blind’s handball against Australia. Defending in the wide area of the 18-yard box, he jumped to block a cross but left his arm trailing behind his body. The ball struck him on the arm, and as the handball rule is currently called, that is a foul and a penalty. But again, a cross into the center of the box is nowhere near an 80 percent scoring opportunity. If it is more than 5 percent I would be surprised.

Of course, there are penalties given where the punishment seems to fit the offense. Luis Suarez’s goal-line handball against Ghana in 2010 is the classic example. More prosaically, when Joao Pereira pulled down Mario Götze inside the box in Portugal’s opening match against Germany, he denied Götze an opportunity to shoot from a central position maybe 12 yards from goal. That’s a big chance denied and a fair penalty.

I suggest that there is a common thread running between the “fair” penalties and the “unfair” penalties. It is the precise location inside the 18-yard box where the foul was committed. While any foul within the box is a penalty, not all areas of the box are equal. I have used the phrase “danger zone” to refer to the central areas of the box. Shots from these regions are scored at rates around 20 percent, and from some areas of the danger zone conversion rates approach 90 percent. Outside the danger zone, shot conversion rates almost never go above a few percentage points.

One simple way to see this is to graph every goal scored at the World Cup. Most were taken from inside the box, but almost none were taken from the wide areas of the box. The danger zone is where goals come from.



Of 87 non-penalty goals scored at the World Cup, 60 have come from the danger zone. Another 16 were attempted from no more than a few yards wide of the danger zone. That leaves just eleven other goals, all of which were scored from outside the box. These numbers are not unrepresentative—similar percentages can be found in league soccer throughout the world. There are exceptionally few goals scored from the widest areas of the box.

Does it make sense that fouls committed in those wide areas of the 18-yard box should be punished equally to fouls committed in or near the danger zone? I think it does not. And so I make my proposal. At 44 yards in width, penalty area is too large. A roughly 30-yard wide penalty area would much better reflect the seriousness of a foul committed within its bounds.

As with any major rule change, there would of course be practical issues to be worked out. But I think one further positive effect would be some diminishing of simulation. There is less simulation inside the danger zone because players who have a real chance of scoring a goal are much less likely to drop to the ground and give up on the play. It’s wide in the box where the incentives get out of whack and diving makes more sense. If you have less than a five percent chance of scoring a goal, why not roll the dice on fooling the referee into blowing a penalty? If fouls in wide areas were punished only with free kicks, players would be more likely to try to stay on their feet.

I think a change in the size of the penalty box would improve the game of soccer.

(Thanks to Alex Olshansky of Tempo Free Soccer for his suggestions that started me down this path.)

All data provided by Opta unless otherwise noted.

Michael Caley writes for Cartilage Free Captain, where he analyzes fancy soccer statistics and bemoans Tottenham Hotspur’s most recent failures. You can follow him on twitter at @MC_of_AMy full World Cup projections and methodology can be found at SB Nation.