Idade dos jogadores e performance na Copa

Following his squad’s early exit, Vicente del Bosque, the Spanish manager, dismissed concerns that his men were over the hill. “This is a mature team with players in their prime”, he insisted. On the surface, the results of the 2010 World Cup seem to confirm that he had little reason to worry. In that tournament, there was no statistically significant relationship between teams’ average age and their final standing. The two youngest teams were Spain and North Korea: one finished first, the other dead last.

However, it is hard to detect the impact of a factor like age using a sample of just 32 teams in a single World Cup, because so many other variables also influence performance. After all, Spain and North Korea differed in every meaningful way except for their average age. In order to isolate the age factor, we must compare teams of otherwise roughly similar skill. One simple way to control for overall quality is to limit the study to defending World Cup champions, all of whom were good enough to win a title four years before the tournament in question.

And within this group, age seems to have a remarkably strong impact. The single strongest factor that influenced their performance was probably the (close to) home-field advantage: teams that played on their own continent performed nearly six places better in the final standings than those that had to travel further afield. But after adjusting for the effect of geography, a one-year increase in average age was associated with a four-place drop in performance (see chart). In other words, if a reigning champion simply brought back its roster from four years before, its mean age would increase by four years, and it would be expected to finish a dismal 17th. Although the sample of title defenders is small, the examples seem compelling. When Italy repeated as the victor in 1938—it is still only one of two teams to win back-to-back Cups—it had the second-youngest team of any returning champion in tournament history. One-third of Cup victors won with an average age below 26, including Spain itself in 2010. Conversely, France in 2002 and Italy in 2010 sent two of the oldest squads, and neither won a single match.

Had the oddsmakers placed greater weight on this variable, they would have been far more bearish on Spain’s chances—and on Argentina’s. The players on this year’s edition of La Roja had an average age of 28, two years older than those who won in South Africa in 2010. Based on that factor alone, they would not have even be expected to reach the quarterfinals. Yet even this rather gray Spanish squad was not the oldest in the 2014 World Cup. That honour goes to Mr Messi and Co.—who have the added misfortune of facing a Belgian team that is the tournament’s second-youngest.

Why do a few piddling birthdays seem to be the difference between triumph and collapse? While there is clearly some value to experience and mastering the intricacies of the game, the raw physical demands of football at the highest level have grown increasingly extreme. In the 1970s players ran a modest four km (2.5 miles) per match; today the figure is over ten. In most other continuous-play sports, managers have the flexibility to rest older veterans to keep them fresh for key moments: the San Antonio Spurs won the National Basketball Association this year by keeping their three biggest stars on the bench 43% of the time. But football’s limit of just three substitutions per match puts a premium on endurance above all else. And it takes a huge amount of guile and technique to compensate for even a small loss of foot speed or stamina. As a result, modern football players tend to peak between the ages of 23 and 25, and are usually well into their decline phase by their late 20s.

Managers are understandably reluctant to leave stars with a relatively recent record of success on the bench or off the team altogether. In addition to prompting an uproar from fans, promoting a green youngster over a battle-tested veteran could easily sow friction among players. But the evidence suggests that managers would be well-advised to kill their darlings at the first opportunity. For all but the most precocious or durable players, even a second World Cup appearance is probably one too many.

Fonte: aqui