Fact or Fiction? 'Form' in Football
Always back a striker in form to score... or should you? A
new book explodes some of the widely held beliefs about the game, as Nick
Harris discovers.
The leading striker at your club – or for your country – has
just banged in a hat-trick. He must be in "form", mustn't he? And thus more likely than average to score in his next game as
well? No, actually. According to a new book, the concept of
"form" in football is a myth. Analysis suggests that the goalscoring runs of even the supposed "hottest"
strikers are no more attributable to a "form streak" than they are to
chance.
The book, Myths and Facts About
Football, draws together academic research from around the world, taking to
task widely held notions about the beautiful game. Many intuitive beliefs are
shown to be flawed. Teams do not run a greater risk of conceding just after
scoring. Home teams in penalty shoot-outs have no advantage. By subjecting what
happens in football to scientific and mathematical tests, economists and
psychologists argue that other "football phenomena" are indeed
provable. Second-leg home advantage in two-legged cup ties is real. Teams that
celebrate goals collectively achieve better results. Penalty takers who shoot
down the middle have the best chance of scoring.
"There really is a gap in the understanding of football
that could be filled with more rigorous scientific analysis of what
happens," says Professor Peter Ayton, a psychologist at
Professor Ayton accepts that the work of "data
fiends" in football is in its infancy, and that only when larger-scale
studies on more aspects of the game are completed will it gain wider
acceptance. But as one of his fellow "fiends" writes in the book's
preface: "Data can tell you far more than commentators, experts, former
players or casual pundits. Objective measurement is not just a way to rank and
value players, but the only way. A statement made about football that can't be
quantified and tested using data is a non-statement. "Over the next 10
years, managers are going to twig to this. When there are millions of pounds at
stake they aren't going to go on valuing players by reading football magazines
and watching a video, are they? So we, the data fiends, are going to take over
the world... Starting with this book."
Fiction: Strikers have periods of 'hot' form when they are
more likely to score
A widely held belief in strikers' "form" was
echoed by a researcher's survey of Premier League players, a large majority of whom believed scoring goals increased the chances of goals
in the next game. But a statistical analysis of goals "by the 12 leading
forwards in the Premiership for 1994-95 and 1995-96 seasons" showed
"no significant association" between one goal and another. For
example, Alan Shearer scored in 79 per cent of home games (34/43). But when he
had failed to score in his previous home game his rate was 85 per cent (17/20).
In other words, his form was "hotter" when he had not scored,
although not significantly hotter, statistically. The same pattern was observed
for Shearer away from home, and overall. The same analysis was done on 11 other
players – Beardsley, Cantona, Fowler, Le Tissier and Sheringham among them
– and "none of the associations for any player, home or away, show a
pattern of scoring such that players are more likely to score if they scored in
their previous game."
Ayton accepts there is a "plausible" logic in the
belief in form – in other words, that goals lead to confidence and goals and a
virtuous cycle – but says it is just as plausible to say that goals lead to
complacency. The stats show neither. "Form" as a generic concept in
football is as likely as "form" for heads or tails in a series of
coin tosses.
Fact: Second-leg home advantage exists
Home advantage is a well established phenomenon across many
sports, including football. But it is also statistically and significantly true
that in two-legged cup ties the overall advantage falls to the team playing at
home in the second leg.
Research led by a London-based French academic, Lional Page, considered 6,182 European ties (12,364
matches) between 1955 and 2006, and found a probability of 53.77 (against an
expected 50) that the home team in the second leg wins. The phenomenon, which
has declined over time, cannot be attributed exclusively to extra time and
penalties in some second legs. One theory is that more is at stake in the
second leg and "home advantage" factors (crowd, familiarity with the
pitch, referee bias) intensify in the decisive, second match.
Fiction: Teams run a greater risk of conceding just after
scoring
The common gesture of a manager pointing urgently to his
head just after his team has scored appears to convey a particular need for
"cool" and "focus" at such times. But a study of 127
Premiership matches finishing 1-1 between 1994 and 1996 showed teams are no
more likely to concede just after scoring than at any other time. The time remaining
after the first goal in each of those games was divided in four. If the myth
were true, more equalisers should be observed in the first quartile. In fact,
that period produced the fewest goals (16.54 per cent), with the highest
percentage (31.5) in the fourth quartile.
Fact: Goalkeepers dive
too often for penalties, as opposed to standing still, which is more effective
Two German economists, Wolfgang Leininger
and Axel Ockenfels, suggest that the very nature of
the penalty kick altered when Johan Neeskens became
the first player in a truly high-profile match – for the
To simplify a hugely complicated subject, the perception of
the "penalty game" shifted from being two-strategy (left or right) to
three (middle as well), and the theoretical chances of success for strikers
rose. One study of 459 penalties in France and Italy from 1997-2000 (Chiappori et al, 2002), showed that kicking down the
middle, on average, has the highest success rate, of 81 per cent, against 70.1
per cent success aiming to the right corner, and 76.7 per cent to the left. But
the convention of "right or left" holds sway, generally. A separate
study by two Israeli academics suggests staying in the centre of the goal might
enhance a goalkeeper's chances of making a save. In a study of 286 spot-kicks,
they observed that goalkeepers who stayed in the middle saved a much higher
proportion of kicks aimed at the middle compared to keepers making dives for
shots placed to the sides. But to simplify again, numerous studies suggest an
"action bias" in goalkeepers: they would rather move and fail to save
than stay put and fail, even knowing that staying put might be a better
strategy.
Fact: Teams who celebrate goals collectively achieve better
results
A psychological study of scorers' behaviour following each
of 125 goals in the Israeli Premier League in 1992 assessed where the player
immediately went (crowd/coach/team-mates), his destination (off field/toward
crowd but not off pitch/where most team-mates were) and number of players making
contact with the scorer. "Post-scoring behaviour was found to be a fairly
good predictor of team success," the researchers found. Whether cohesion
equals success, or vice versa, needs further study, although coaches are
advised that post-scoring behaviour can provide "useful information about
the players' attitude towards the team".
Fiction: Taking the lead just before half-time makes a win
much more likely
An analysis of Premiership games between August 1992 and
October 1995 showed that 355 matches had a 1-0 scoreline
at half-time. A survey of Premier League players showed that footballers had a
belief that scoring just before half-time was better than earlier in the game.
But the researchers say: "The time when that goal was scored doesn't have
any effect on the game; rates of win, lose or draw
hardly vary at all [statistically] as a function of when the first goal was
scored." However, while this study suggests that success via late
first-half goals is myth, Professor Ayton also cites a larger, more recent
study, of almost 20,000 games, that suggests a discernible, but not large,
advantage in scoring just before half-time.
Fact: Player performance is strongly affected by relative
income
Or in other words, when a player's salary rises (or drops)
relative to his team-mates' pay, his performance improves (or declines). German
and Swiss economists demonstrated this by studying goals, assists and ball
usage (and salaries) of players at 28 clubs in the German Bundesliga
between 1995 and 2004. The "robust findings" show the relationship is
not simply that "better players earn more" but that the
"causality runs from pay to performance, not the other way round".
Willingness to perform, as in many jobs, depends on relative pay.
Fiction: Starting a penalty shoot-out is an advantage
A study into performance under pressure examined 95 penalty
shootouts in the German FA Cup between 1986 and 2006. The results found
"no grain of truth" in the idea that taking the first kick in a
shoot-out held any advantage. Nor did home teams fare any better,
statistically, than visitors. The researchers said: "It is particularly
noteworthy that the relative frequency of the home team winning in a shoot-out, is, in fact, considerably smaller than the frequency of
home teams winning in a match during the regular season... 'choking'
could influence penalty conversion of home team players negatively."
'Myths and Facts about Football: The Economics and
Psychology of the World's Greatest Sport', edited by Patric
Andersson, Peter Ayton and Carsten
Schmidt (Cambridge Scholars Publishing), will be published on 1 November. Paperback £12.99; hardback £39.99. Available via www.c-s-p.org, at amazon.co.uk, or order in any
bookshop (ISBN 9781847186225)
Article taken from
‘The Independent’ on Wednesday, 8 October 2008