The ultimate test of nerve under pressure, penalty shootouts have long provided dramatic climaxes to some of football’s most high-profile competitions. As the knock-out stages of Euro 2012 approach, we assess whether there is a science behind the apparent "lottery" of penalties.
The Science of the Spot
As players and observers alike begin to subject shootouts to an unprecedented level of scrutiny, Prozone has conducted an in-depth study into the numbers behind the drama which includes analysis of:
- Every World Cup and European Championship shootout since 1998
- 3 key shootouts from 2011/12: Carling Cup final, Champions League Semi-Final and Final
- Scoring zone percentages
- A breakdown of success by footedness
- Save frequency by direction
- The relationship between run-up length and conversion
- How on-field minutes affect penalty performance
There has certainly been a shift towards more performance analysis with regard to penalties in recent years. The book Soccernomics, co-authored by Simon Kuper and Stefan Szymanski, includes a chapter that takes an empirical look at the process of penalty shootouts, its most significant finding being that the team that takes the first penalty wins over 60% of contests.
Goalkeepers have also started to more thoroughly prepare for shootouts, Ben Foster making headlines during the 2009 Carling Cup final when the then-Manchester United ‘keeper watched a video of Tottenham Hotspur’s penalty takers on his iPod in the moments before the first kick. After correctly guessing the direction of all five penalties in the Blues’ Champions League triumph in Munich, Petr Cech revealed that he had watched a two-hour DVD of every penalty taken by a Bayern player since 2007, while Huddersfield Town’s Alex Smithies had notes taped to his water bottle during the marathon League One play-off final shootout.
Tom Heaton has spoken about the analysis he undertook ahead of Cardiff City’s Carling Cup victory over Crystal Palace:
“The footage made me aware of the style players have when taking penalties and where they have put them in the past,” said Heaton. “I mixed that knowledge with judgement on the night, looking at the body shape of Palace players as they prepared to take their penalties.”
Having called upon Prozone’s data archive in an attempt to identify proclivities in the numbers, analysts have identified a series of fascinating trends which question whether penalties really are random games of chance as many would have us believe.
If in Doubt, Go First
One of the clearest patterns to be deduced from the figures was, in accordance with the findings of Soccernomics, the apparent advantage of the team that takes the first penalty. Of the shootouts studied, the team that went first scored 76.9% of their penalties to the 68.4% scored by teams going second, with the team taking the first kick winning 75% of the time. There is an even stronger correlation between missing first and defeat, the side that did so losing 81.2% of the shootouts included in the data set.
There is no single catch-all reason for why such an advantage lies with the team that take the first penalty, but one possible explanation is that the team going second is constantly playing catch-up with its opponents. During a shootout it is arguably more unsettling to be confronted with the possibility of terminal failure ― a situation frequently faced by the team going second ― than to still have the hope of redemption with another kick to come. Indeed, the figures add some weight to this theory. Of penalties taken to win shootouts, a staggering 81.2% were scored in comparison to the paltry 14.2% converted when a team had to score to keep the game alive. When we assess this in relation to the average penalty success rate of 68.9%, we can surmise that triumph is a lesser burden than disaster where penalties are concerned.
Interestingly, while the unique context of any given kick may play a role in its success or failure, the result of the penalty taken by the previous teammate does not appear to impact upon the prospects of the following attempt. In situations where the preceding kick had been missed, teams scored 65.6% of their penalties, with a marginally inferior 65.4% being converted following a successful attempt.
The Way to Go
There has long been debate about which side of the goal players should hit their penalties and the frequency with which they should change their approach in order to give them the best possible chance of success. In the age of video analysis, with the habits of regular takers closely monitored by opponents, decisions made from the spot need to be more strategic than ever before. With this in mind, the available penalty data has been broken down to highlight the statistically most effective (and most dangerous) areas for players to aim for.
In terms of location, the bottom left corner (the strong side for right-footed players) proved the most rewarding, with 18.7% of all successful kicks in the sample finding that part of the goal. In fact, the entire left side of the net proved highly effective, 40.3% of all converted penalties being hit there against 35.1% on the right and 24.6% down the middle. To go to the next level of detail, if the kicks are arranged by the footedness of the takers the pattern that emerges is one which suggests that right-footed players are more versatile from the spot than their left-footed counterparts.
Hitting to their strong side 38.6% of the time, right-footers shot to the left more often than the overall average (37.2%), but also went either right or down the middle with 61.5% of their penalties. In contrast, left-footed players hit to the right (their more comfortable side) with exactly half of all their penalties, a figure which suggests that they are perhaps less willing to vary their approach and so are statistically more predictable for goalkeepers looking to inform their natural intuition with objective analysis.
While aiming low may give penalty takers the best statistical chance of success, they are also the kicks most frequently saved. Given that goalkeepers rarely stay in the middle of the goal, they tend to dive ― by the very nature of the action ― in the bottom third of the target area and have been shown to guess correctly 47.2% of the time. This is reflected in the data which shows that 71.4% of all saves came in the lower part of the goal, with 32.2% occurring in the bottom right corner alone. None of the penalties hit at the upper third of the net were saved, a statistic which demonstrates that if a player is confident enough in their ability to hit the ball high and on-target, they are virtually guaranteed to score.
Power versus Placement
Prozone analysts have also looked at the way in which each of the penalties in the sample were struck. The results show that side footed kicks and those taken with the laces remain relatively close to the average success rate of 68.9%, although there are slight fluctuations with each. Despite being more difficult to direct, shots hit with the laces for added power were 69.3% successful, with placed kicks falling below the average to 68.4%.
This data tells us that, although placement affords the taker greater control over their penalty, powerful shots are more difficult for goalkeepers to read and react to. However, players opting for power should be wary of taking a long run-up as ‘keepers guessed correctly on 54% of the penalties where the player began their approach from outside the area, run-ups from the edge of the box being pre-empted just 40% of the time. With that in mind, it is possible to call on the data to construct a hypothetically ideal penalty kick.
The three-step guide to a statistically perfect penalty:
- Medium-length run-up from the edge of the area
- Hit with power
- Aimed at the bottom left corner
As well as providing insights regarding the direction and results of penalties, Prozone analysed the success rates of different groups of players and the contrasts between kicks taken at different stages of shootouts. It was discovered that attackers converted 79.5% of their penalties, with midfielders and defenders trailing at 63.2% and 63.3% respectively, while the physical condition of players also appears to have some effect on performance. Penalty takers who had played more than ninety minutes scored just 66.3% of their kicks, whereas those who had played between 45 and 90 minutes fared the best with a conversion rate of 75%.
Another fascinating trend was the observation that the success rates for the first and fifth penalties were far higher than those recorded for the second, third and fourth. The first penalties were scored 81.2% of the time, with the fifth kicks having the strongest rate of success at 87.5% and the other three mustering an average of just 61.5%. This evidence suggests that teams generally put their strongest penalty takers at the start and finish of a shootout in order to get off to a good start and best perform under pressure should the last kick be needed to stay in or win the game.
Knowledge and Control
Of course, no matter how much research and analysis is done into penalty shootouts, they can never be flawlessly forecast. While there are several significant trends visible in the data sample assessed by Prozone, they are simply indicators of habit rather than a concrete blueprint for success. As Chelsea’s victory over Bayern Munich after taking the second penalty and missing first demonstrated, there will always be outliers to the patterns that are observed. The element of unpredictability inherent in shootouts can never be fully expunged, but it can at least be partially limited.
Although there is no magic formula for success in penalty situations, specific analytical preparation is ― as the testimonies of elite goalkeepers attest ― undoubtedly beneficial. When taking part in something so apparently random, anything which increases the amount of information and control that can be brought to bear on the situation could provide the crucial difference between victory and defeat.
Since 1998 Prozone has been delivering detailed performance insights to football clubs operating in an increasingly competitive environment. Providing a comprehensive service to over 240 clubs in 39 countries worldwide, Prozone’s market-leading range of analytical products are a trusted source of objective analysis at the game’s elite level.
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