Tuesday, July 15, 2014

The Pressure of the World Cup Penalty Kick

Tim Howard was brilliant in goal for the United States at the 2014 World Cup. Flying all over the place, catching, punching, kicking – he looked like he was protecting his family home from post-apocalyptic cannibals. It was very impressive, but the US went out against Belgium 2-1 in extra time, despite Howard’s 17 saves, the most in a single World Cup game in 50 years.

Tim Howard had a great game for the US, heck, a great 
tournament. So great in fact, that Wikipedia temporarily 
changed the name of the US Secretary of Defense to 
Tim Howard. The true SOD, Chuck Hagel, called to 
congratulate Howard. Hagel stated that with some
training, Howard could be the real secretary of 
defense. One, he called after a loss – reminds too many 
people of Vietnam, and two, what few things does 
Howard lack to be SOD?
In the whole of Team USA’s tournament, Howard didn’t face one penalty kick. This was good for him, since it’s so hard for a goalie to look invincible against a lone player kicking a small ball into a 24 foot (7.3 m) wide goal from only 12 yards (10.9 m) away.

In World Cup competition, most penalty kicks are successful, to the tune of about 86%. But penalty kicks come in two flavors, and that percentage only reflects the scoring rate for penalty kicks (PK) that occur during the game. There are also PKs that come when the two teams are still tied after extra time (we Americans call it overtime, but of course we call it soccer too).

About 70% of penalty kicks find the back of the net in that situation. Why is there a difference? It’s the same distance, it’s still striker against goalie. The ball is still roughly round with those funny geometric shapes stitched into it. Why does the scoring rate go down so significantly?

Billy Joel told us why many years ago – Pressure! The kicker is expected to make the shot – he has such a big advantage. Joe Bag–O-Donuts on his couch is screaming that he could make that shot, and he gets out of breath just opening the chip bag! Let’s investigate how big an advantage the striker actually has, and then we can figure out why it shrinks when it’s time to line up for PKs.

Billy Joe’s song has some poignant lines that could apply
to penalty kicks. “So far so good but you will come to a
place where the only thing you feel are loaded guns in
your face and you'll have to deal with pressure.” Or how
about, “Don't ask for help you're all alone. Pressure.
You'll have to answer to your own pressure.”
A good college or professional football player will kick the ball so it reaches a speed of 80 mph (128 kph, or 117 feet per second/35.7 meters per second). At a distance of 12 yards, this means the whole event is over in roughly 0.3 seconds. It takes a goalie about 0.6 seconds to move so that one hand or foot can get to either edge of the goal! You don’t have to be a math magician to see that if the striker can kick the ball on target, it’s going to go in.

That’s why most PKs are aimed at the edges of the goal, either up top, in the middle, or on the ground. Most PKs that are missed are aimed up high, so maybe the goalie has a slight advantage there, but still, there’s 192 square feet (17.9 square meters) of space that must be defended in the blink of an eye. Yes, it takes 0.3-0.35 seconds to blink – let’s hope the goalie’s eyes don’t have bad timing.

FIFA changed the rule in 1997 so that the goalie can move before the ball is struck, but it doesn’t help that much. He still isn’t allowed to move forward. This would help him narrow the angles and reduce the square footage he has to defend. And if he does move before the ball is kicked, he’s really just guessing. A study of previous World Cups says that goalies only guess correctly about 41% of the time, and guessing right still doesn’t matter if he doesn’t have enough time to get a hand on the ball.

Some goalies say that they can watch the striker to get a
sense of where he is going to kick the ball. They contend
that the kick usually goes the same direction that the plant
foot is pointed. Of course, strikers know this. So what do
you think they do? And of course, they can hesitate in their
run up to see which way the goalie is leaning.
Research at Brunel University in London suggests that World Class goalkeepers can anticipate a striker direction about 80 milliseconds (0.08 s) before he kicks it. Is this enough of an advantage to stop a well placed shot? Maybe, but probably not.

But goalies do have some recourse. A study by Noel and Vander Kamp (2012) suggests that focus is the key. By making large movements or sudden moves, a goalie might just be able to distract the striker and send the shot errantly wide or high. The study for International Journal of Sports Psychology showed that strikers that spent slightly more time looking at the goalkeeper as opposed to the ball or target area were stopped more often.

Their research suggested that taking a goalkeeper-independent strategy (ignore him/her completely) was better for making goal kicks. So the more a goalie can make you look at him, the better. Maybe that’s why they wear bright colors.

Greg Woods’ PhD thesis for the University of Exeter also points to a focus issue. He used 18 college football players fitted with eye tracking software. If the striker looked at the goalie, the penalty kick was stopped 40.6% of the time, while if he ignored the goalie, the shot was only stopped 20% of the time.

Eye tracking is important in sport science, but also in business
marketing. People trying to sell you things you don’t need want
to draw your eye to the things they want, so they need to know
where you look and when during commercials. The camera that
faces forward  shows what you are looking at, and the camera
facing your eye tracks your pupil. The two can be coordinated
so they can see what portion of your field of vision your pupils
are focused on. They are accurate to about 0.1 in (2.5 mm) at 30
inches away from the screen.
But is this enough to explain the big decrease in PK success at the end of games? The added pressure of having no time to make up for mistakes increases the anxiety level of the strikers and helps the goalie even out some of their disadvantage.

The statistics bear out the pressure angle. The coin flip is important before PKs because 80% of the time, the team that kicks first, wins. Every time the first team is successful, the pressure ramps up on the second team, because now they’re playing from behind. Statistics also show that the first team that misses will lose about 81.2% of the time. The added pressure of being behind is too much to overcome.

The added pressure results in a breaking of rhythm that overcomes the muscle memory that should control a striker’s kick. It may also increase the time that a striker is unfocused, and may look at the goalie more. Woods’ study, published in the Journal of Sport and Exercise Psychology (2009) showed that as anxiety increased, the striker was more likely to spend time looking at the goalkeeper, and this tended to send PKs more centrally in the net and therefore easier to stop.

You can see by the look on his face, Andres Escobar knew
something bad just happened. His block ended up in his country’s
goal. He returned home to Colombia only to be shot a couple of
days later. ESPN made a documentary about the two Escobars,
Andres and Pablo, and suggested that Andres would not have
been killed if the drug lord, Pablo, had not died a few months
previous. Pablo was a soccer fan, and many of the national team
players were his friends.
The pressure of playing for your country in the World Cup may also be an added bonus; some countrymen just won’t let a guy forget a World Cup gaffe. Andres Escobar was shot dead in Colombia just days after returning home from the World Cup in 1994. His own goal (hit the ball into his team’s net) sent the Colombian team home after group play.

Another Colombian player was murdered in 2006 in a bar shooting. He had missed a penalty kick in the Copas Libertadores tournament a few years earlier, of course the motive for the shooting might have been something else. The moral of the story – ignore the goalie and don’t forget your bullet-proof vest.

Contributed by Mark E. Lasbury, MS, MSEd, PhD
Mark is writer and educator in the areas of science and history
As Many Exceptions As Rules

Wilson MR, Wood G, & Vine SJ (2009). Anxiety, attentional control, and performance impairment in penalty kicks. Journal of Sport & Exercise Psychology, 31 (6), 761-75 PMID: 20384011

BENJAMIN NOËL and JOHN VAN DER KAMP (2012). Gaze behaviour during the soccer penalty kick: An investigation of the effects of strategy and anxiety Int. J. Sport Psychol., 41, 1-20

1 comment:

  1. This article was interesting for me to read as we just read about stress and how it can affect us both mentally and physically. The goalie must feel such a tremendous amount of stress during the world cup penalty kick. Essentially having the outcome of the game fall solely on your shoulders. From what I learned in psychology if you expose yourself to small amounts of stress ( their other games) it helps to protect the mind and body from the harmful effects of stress.