Football penalties: science is on the spot

May 10, 2010 by Richard Ingham
Chelsea's Frank Lampard (left) scores a penalty shot past Aston Villa's goalkeeper Brad Friedel during their English Premier League match at Stamford Bridge in London, on March 27. The perfect penalty, a mathematical study found, is a ball that is struck high, targeted precisely to the right or left of the goalie, and fast, travelling at 25-29 metres per second.

Few moments in football are as extraordinary as the penalty, the moment when a dream can crumble or glory is made - and a player is either cursed as a choker or enters the pantheon of legends.

In the nearly 119 years since the very first penalty kick, in a match between Wolverhampton Wanderers and Accrington Stanley, the 11-metre (12-yard) spot has determined more and more tournaments, including the 2006 World Cup final.

As the importance of the penalty has grown, so has research. Scientists see it as a duel between shooter and goalkeeper where and psychology can give either side a critical edge.

A mathematical study of penalties at Liverpool's John Moores University puts the death nail into the "blast-it-and-hope" approach.

The perfect penalty, it found, is a ball that is struck high, targeted precisely to the right or left of the goalie, and fast, travelling at 25-29 metres per second (90-104 kilometers or 56-65 miles per hour).

Anything faster than this boosts the chance of a miss because of inaccuracy, while anything slower helps the goalie to intercept it.

Moving swiftly to take the penalty (less than three seconds after the whistle is blown) gives the striker the element of surprise, while delaying the strike by more than 13 seconds makes the keeper unsettled, according to the researchers, who looked at decades of international matches involving England.

Waiting for the goalkeeper to move also boosted chances. However, waiting longer than 0.41 milliseconds caused a scoring chance to be halved. A runup of four to six steps was the most successful approach, while a long runup of 10 metres (yards) was the least.

Seen only through the prism of statistics, the balance in penalties is tilted massively in favour of the taker: between two-thirds and three-quarters of strikes result in a goal, according to various analyses in top-flight European club soccer.

But in a counter-intuitive way, these figures also give the psychological advantage to the keeper. If the penalty succeeds, people will pat him on the shoulder and say hard luck, because few expected him to save it. If he does save it, he will be praised to the rafters. In other words, all the onus lies with the penalty-taker.

This problem was explored last year by a team at the University of Exeter in southwest England, which asked members of the university squad to wear special glasses, recording eye movements, while they took two series of penalties.

In the first series, the players were simply asked to do their best to score. In the second, they were told the results would be recorded and shared with the other players, with a bounty of 50 pounds (72 dollars, 57 euros) for the best penalty-taker.

The more anxious the penalty-taker was, the likelier he was to look at, and focus on, the centrally-positioned goalkeeper. And because gaze control and motor control are tightly coordinated, the player's shot also centralised, making it far easier for the shot to be saved.

"The optimum strategy for penalty takers to use is to pick a spot and shoot to it, ignoring the goalkeeper in the process," said lead researcher Greg Wood.

Practice is essential, he said. The Hungarian great Ferenc Puskas would train again and again, shooting at a 25-centimetre (one-foot) disc hung 80 centimetres (a yard) from the bar.

"The idea that you cannot recreate the anxiety a penalty-taker feels during a shootout is no excuse for not practising," said Wood.

"Do you think other elite performers don't practice basic aiming shots in darts, snooker or golf for the same reasons? The skills need to be ingrained so they are robust under pressure."

As for helping the goalie, experiments suggest looking at a players' hips during the end of the runup gives a tip as to where the ball will be struck. Researchers at the University of Hong Kong also suggest that if a keeper moves just six to 10 centimetres (three to five inches) off centre, that is enough to tempt the taker into directing the kick to the side of the goal where there is more space.

There are also mind games, such as shuffling or taking time to prepare for the shot, to distract the penalty-taker.

Even clothing colour is thought to be a help: Petr Cech of Chelsea prefers a bright orange strip in the belief that it attracts opponents and make them likelier to shoot straight at him.

That belief is bolstered by sports psychologists at the University of Chichester, southern England, who asked 40 footballers to take dozens of penalties over a week against a single keeper who changed strip. When the keeper wore red, only 54 percent of the penalties scored; for yellow, it was 69 percent, for blue 72 percent and green 75 percent.

Why? Red is associated with danger, dominance or anger, and at times of stress we pay more attention to it in our environment, goes the theory.

Explore further: Heat distributions help researchers to understand curved space

add to favorites email to friend print save as pdf

Related Stories

Why England's soccer team keeps losing on penalties

Dec 11, 2009

A new study may explain why the England soccer team keeps losing in penalty shootouts - and could help the team address the problem in time for the World Cup 2010. Research by the University of Exeter shows ...

Death Penalty Does Not Deter Murder, According to New Study

Jun 17, 2009

Eighty-eight percent of the country's top criminologists do not believe the death penalty acts as a deterrent to homicide, according to a new study published today in Northwestern University School of Law's Journal of Criminal ...

What computer science can teach economics

Nov 09, 2009

(PhysOrg.com) -- Computer scientists have spent decades developing techniques for answering a single question: How long does a given calculation take to perform? Constantinos Daskalakis, an assistant professor ...

Recommended for you

Has microfinance lost its moral compass?

2 hours ago

The industry that provides financial services for people on low-incomes and without access to traditional banking services is morally reprehensible according to new research from The University of Manchester.

One of world's earliest Christian charms found

3 hours ago

(Phys.org) —A 1,500 year-old papyrus fragment found in The University of Manchester's John Rylands Library has been identified as one the world's earliest surviving Christian charms.

Study claims cave art made by Neanderthals

18 hours ago

A series of lines scratched into rock in a cave near the southwestern tip of Europe could be proof that Neanderthals were more intelligent and creative than previously thought.

User comments : 2

Adjust slider to filter visible comments by rank

Display comments: newest first

Bob_B
not rated yet May 10, 2010
Football? Oh, soccer. The sport that is like Irish dancing...no arms.
trekgeek1
not rated yet May 10, 2010
So a good kick is up where they can't reach it, way to the side where it's hard to get to, and fast so the goalie can't react, but not so fast that it's beyond your control. WOW!! It all makes sense now. I would've thought straight at the goalie, chest level, and lazily arced. These results seem a bit obvious.