足球教练 ＝ 战术大师 么 ？

一项最新的研究表明，足球教练为了避免一场意外失利而换上新球员通常会事与愿违。

研究人员分析了德甲1998/99到2009/10十二个赛季的3672场比赛，以及英超2000/01到2011/12十二个赛季的4560场比赛中赌博公司更青睐获胜一方的球队表现。

他们发现换上替补球员不但没有什么用，而且有85%更高的可能因为暴力行为而吃牌。

华威商学院LeifBrandes，苏黎世大学Björn Bartling，缅因大学DanielSchunk的研究表明，专业足球教练通常被视为战术大师，但往往在为避免意外失利时会犯下错误。

Brandes 博士说：“我们的研究表明教练会通过换人的方式来改变战略部署，用一名前锋换下一名后卫更多的发生于意外落后时。

虽然换上前锋是希望反败为胜，但是这通常会导致更糟糕的结果，他们的失球平均增加了0.3，分数损失也增加了0.3.

同时，他们也犯规更多，吃牌更多，每分钟多14％的吃牌概率。这样以来他们的失球失分反而会更多。

在即将发表在Management Science的论文Expectationsas Reference Points: Field Evidence from Professional Soccer中，研究人员通过英超德甲数据分析，测试了“参考分数行为”模型。

这一模型表示，如果人们期待本应发生的结果却没有发生，他们为达到此结果而做出的决策往往不理智。

Brandes博士说，这在足球比赛中经常发生。现实生活中人们被既有期望而影响。

“回到足球上，这些教练和球员拿着巨额工资每周在上万名现场球迷面前比赛，由于既有期望没有达成，他们往往会冒风险，而这回导致他们心理上的巨大压力，做出的决策和举动也会失去理智。以前类似的理论在特定的环境中被提出，但是我们对于足球球队的研究表明现实生活中亦是如此。”

研究同样发现英超（每场2.63）的进球比德甲（每场2.85）要少，拿牌也相对较少（英超3.26张，德甲4.31张）。换人方面，英超同样也更少（4.89对5.46），而且他们的进攻意识也稍弱。但在这两个联赛中，受赌博公司青睐的球队在落后时都会有不理智的行为发生。

Brandes博士表示，这一影响是巨大的。由于意外落后和裁判发生口角而吃牌的概率上升了43%，暴力行为上升了85%。相较而言，如果受青睐球队落后时，如果发生浪费时间，或者没有间隔定位球特定距离，裁判出牌的概率分别下降了75%和74%。

这篇文章同样发表在The Independent, Yahoo News and MSN.com

Leif Brandes博士教授华威EMBA市场营销课程，以及本科国际市场营销课程。

Football managers aren't tactical geniuses after all

Football managers bringing on substitutes to avoid a shock defeat actually make things worse,according to new research.

The researchers looked at what the bookies’ favourite did in 3,672 matches in the German Bundesliga over12 seasons from 1998/99 to 2009/10 and 4,560 games in the English PremierLeague in the 12 seasons from 2000/01 to 2011/12.

As well as throwing on subs that didn’t come off, they found that teams heading for a shock defeatwere 85 per cent more likely to receive a card for violent conduct.

Many professional football managers are often seen as tactical geniuses, but Leif Brandes, ofWarwick Business School, Björn Bartling, of the University of Zurich, andDaniel Schunk, of the University of Mainz, found that they make mistakes whentrailing to a side they are expected to beat.

Dr Brandes said: “Our research shows that coaches implement offensive strategy changes by means of substitutions, for example a striker fora defender, significantly more often if their teams are behind expectationsthan if their teams are not behind expectations.

“Despite the push to bring on another striker to help bring the score back in favour of the teamexpected to win our research found such an action actually had negativeconsequences, with on average it worsening their goal difference by 0.3, whilethey were also 0.3 points worse off.

“When the bookies favourites are behind we found they also receive more cards, 14 per cent morecards per minute. This, plus substituting players in an offensive way whilebeing behind expectations sees them concede more goals and give up morepoints.”

In the paper, Expectations as Reference Points: Field Evidence from Professional Soccer, due to be published in Management Science, the academics tested amodel of ‘reference dependent behaviour’ by analysing 8,200 matches in the topfootball divisions of Germany and England.

This model states that if people are expecting a certain outcome and it doesn’t happen they don’t alwaysact in a rational way to get back to that expected outcome。

Dr Brandes said: “This is exactly what we see with football teams when they are the favourites to win.Our research shows in real life how people are affected by expectations.

“After all, these players and coaches are paid huge sums of money to play each week in front of a massiveaudience, and this shows they can experience psychological distress and actirrationally by taking too much of a risk when expectations are not beingreached. Previously this has only been seen in a controlled environment, butour study of football teams reveals it happens in a real-life situation.”

The study also found fewer goals are scored in the Premier League compared to the Bundesliga, with 2.63 goals per match in England compared to 2.85 in Germany andfewer cards are handed out (3.26 cards per match compared to 4.31). Alsosubstitutions are somewhat rarer in England (4.89 per match compared to5.46) and they are less attack-minded.

But in both countries when the bookies’ favourite is losing they lose their cool.

Dr Brandes said: “The size of the effect is considerable. Cards for ‘dissent’ increase by 43 per cent if a team isunexpectedly behind, while violent conduct offences rise by 85 per cent.Conversely, when the favoured team is losing, time wasting or not retreatingfrom a set play properly, the number of cards issued falls by 75 per cent and 74 per cent.”

See this article featured at The Independent, Yahoo News and MSN.com

Dr Leif Brandes teaches Marketing onthe Warwick Executive MBA and International Marketing on Warwick Business School's Undergraduate programme.

To read more about WBS articles, please click "Read More"

想要了解更多华威商学院研究成果，请点击下方“阅读原文”