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Home advantage in Turkish professional soccer
Home advantage in Turkish professional soccer1
Aylin Seckin
Istanbul Bilgi University
Richard Pollard
California Polytechnic State University
San Luis Obispo, California
1 Address correspondence to Richard Pollard, 2401 Cloverfield Boulevard, Santa
Monica, CA 90405, USA or e-mail (richwpollard@yahoo.com).
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Summary.-Home advantage is known to play an important role in the
outcome of professional soccer games, and to vary considerably worldwide. In
the Turkish Super League over the last 12 years, 61.5% of the total points gained
have been won by the home team, a figure similar to the worldwide average and
to the Premier League in England. It is lower (57.7%) for games played between
teams from Istanbul and especially high for games involving teams from cities in
the more remote and ethically distinct parts of Turkey (Van and Diyarbakir).
Match performance data show that although home teams in Turkey take 26%
more shots at goal than away teams, the success rates for shots do not differ. For
fouls and disciplinary cards, home and away teams do not differ significantly in
Turkey, a finding that that differs from games in England, perhaps due to less
referee bias.
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Home advantage is an important factor in the outcome of soccer games,
although its precise causes are not clear. The main factors involved fall under the
general headings of crowd support, travel effects, familiarity with local playing
conditions, referee bias, territoriality, and psychological effects. The evidence for
and against these factors are summarized in Pollard (2006a) and a model for the
way in which they are likely to interact with each other is proposed. In national
leagues worldwide, there is wide variation in the extent to which the home team
derives an advantage (Pollard, 2006b). This advantage is unusually high in the
Andean nations of South America and in the Balkan countries of Europe, where
over 70% of points gained are won by the home team. This compares with a
worldwide average figure of 61%. A heightened feeling of territoriality has been
advanced as an explanation for the increased Andean and Balkan advantage.
The increasing availability of detailed match performance data allows more
light to be shed on the way in which team performance indicators differ between
the home and away teams. Carmichael and Thomas (2005) used such data from
the Premier League in England to show that the home team had significantly
higher figures for attack indicators, such as shots and successful passes in the
scoring zone. Conversely, the away team committed significantly more fouls and
suffered more red and yellow cards.
Thus far, most detailed research into the home advantage in soccer has been
confined to professional soccer in England. An in-depth analysis of the home
advantage is now provided for Turkey, which can be interpreted in the context of
what is known in England. Turkey is now a major soccer playing nation, with the
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national team finishing third in the 2002 World Cup. The top teams in the
Turkish league regularly reach the group stages of the Champions League in
Europe. A preliminary analysis of match performance data now available from
the Turkish Super League has been made by Seckin (2006).
DATA AND METHODS
A complete record of all games played in the Turkish Super League was
obtained from an established and reliable website2 for the 12 seasons 1994-95 to
2005-06. This period was chosen for the study since the Turkish league expanded
to 18 teams in 1994-95. Since then, the league has operated with the same 18
team format, with each team playing the other once at home and once away
during the season. This balanced structure allows an unbiased quantification of
home advantage to be made. The same structure has been used in League A since
2002-2003, providing four seasons for use in this study. Promotion and
relegation operate at the end of each season between the Super League and
League A, the top two tiers of soccer in Turkey. Comparative data for the
Premier League in England was obtained from the same source. The match play
data for teams in the Turkish league was provided by the sports data company
FSTATS3 for the season 2005-2006. Data from five of the 306 games played
during the season were incomplete and were omitted from the analysis.
2 www.soccerway.com
3 www.fstats.net
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Comparable data for the Premier League in England was generated by the Opta
Index and reported by Carmichael and Thomas (2005) for the season 1997-98.
The calculation of home advantage follows the procedure adopted by Pollard
(2006a). The overall home advantage in a balanced league can be quantified as
the total number of points obtained by home teams expressed as a percentage of
the total number of points gained in all matches. For an individual team, this
becomes the number of points won at home expressed as a percentage of all
points won by that team. The same calculation is used for groups of teams in
specific matches, such as for London-based teams playing each other in local
derbies. Comparisons in home advantage are made between leagues and as a
function of distance travelled, specifically for local derbies and for teams in
remote locations.
For the match performance indicators, comparison of home and away teams
was made using paired sample two-sided t tests. Proportions were tested using
the standard normal distribution. Effect size was estimated using Cohen’s d
statistic.
RESULTS AND DISCUSSION
The overall 12-year figures in the two leagues are very similar to each other,
61.5% in Turkey and 61.0% in England. This is also very close to the worldwide
figure of 61.5% reported by Pollard (2006b), although slightly below the other
major domestic leagues in Europe. Home advantage in League A in Turkey for
the most recent 4-year period is 61.4%, which is almost identical to the higher
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level Turkish Super League. However, this is consistent with other second level
leagues in Spain, England, Germany, France and Italy where home advantage is
generally at least as high as in the top-level leagues (Pollard, 2006a).
During the 12-year period under study, home advantage for Super League
games played in Istanbul between Istanbul teams (“local derbies”) was 57.7%,
lower than the figure of 61.7% for all other games in Turkey (z = 1.54, p = .06).
Figures for the Premier League in England for the same period, comparing
London derbies with all other games, were 55.5% and 61.3% (z = 3.47, p < .001).
Thus in both countries the advantage of playing at home was lower in local
derbies than in other games. This is consistent with expectation if one assumes
that crowd support will be more evenly balanced in these games and any adverse
effects from travel will be minimized.
Teams in remote locations may derive more advantage from playing at home,
both as a result of increased travel effects and a heightened sense of territoriality
(Pollard, 2006b). Four such locations were selected in Turkey and home
advantage calculated for their local teams when playing in the Super League
during the 12-year period under study. The results were Trabzon (55.5%), Rize
(67.5%), Diyarbakir (68.1%) and Van (76.5%). Thus three of these locations had
home advantage figures substantially higher than the overall league average of
61.5% (all p < .05). Of particular interest is the city of Van, whose local team,
Vanspor, played in the Super League for 5 seasons in the 1990s and had an
usually high home advantage figure of 76.5%. Situated in the extreme east of
Turkey at an altitude of 1,750 m, with a harsh winter climate and a violent,
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bloody history, Van has much in common with towns in the Balkan countries
where home advantage is also extremely high (Pollard, 2006b). This may be due
to a heightened sense of territoriality, defined as a “protective response to an
invasion of one's perceived territory” and discussed in the context of soccer by
Neave and Wolfson (2003). Home advantage for the team from Diyarbakir is also
high (68.1%). Since the city has a large Kurdish population as well as a history of
conflict, territoriality could again be advanced as a contributing factor.
The match performance analysis for the Turkish Super League in 2005-06 is
summarized in Table 1. For each performance indicator, the season total for
home and away teams is given, followed by the percentage by which the home
figure exceeds the away, and the corresponding values of t and p, together with
the effect size d. The match performance figures for the Turkish Super League
suggest, not surprisingly, that home teams have significantly higher figures on
variables that capture the extent to which a team is in attacking positions near the
opponents' goal. Shots are 26% higher than for the away team, and successful
passing in the scoring zone 11% higher. However, the effectiveness of shooting
is no different for home and away teams, both as measured by the proportion of
shots on target and by the proportion producing goals. In contrast to the attack
indicators, there are no significant differences between home and away teams for
any of the four aggressive indicators, tackles, fouls, and yellow and red cards.
In the English Premier League the performance indicators showed a more
clear-cut difference between home and away teams, especially for fouls and the
disciplinary cards. For fouls, the magnitude of the differences between home and
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away teams does differ significantly between Turkey and England (z = 3.72, p <
.001). The same applies to yellow cards (z = 4.33, p < .001), but for red cards the
much smaller sample sizes did not produce a significant difference. These results
should be interpreted with caution since they are based on a single season for each
country, and at a different time. Nevertheless, referees in England have been
shown to be more lenient in penalizing the home team, both with free kicks
(Nevill, Balmer, & Williams, 2002) and yellow cards (Dawson, Dobson,
Goddard, & Wilson, 2007). Thus a possible explanation for the differences found
between the two countries is that decisions by Turkish referees are less influenced
by the reaction of the home crowd to opponents’ tackles, possibly a consequence
of smaller and less dense crowds. Whatever the reason for the differences with
regards to these aggressive indicators, the net effect on home advantage seems to
be small, since the differences between home and away teams in terms of shots
and goals, as well as points, are very similar in Turkey and England.
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REFERENCES
CARMICHAEL, F., & THOMAS, D. (2005) Home-field effect and team
performance. Journal of Sports Economics, 6, 264-281.
DAWSON, P., DOBSON, S., GODDARD, J., & WILSON, J. (2007) Are
football referees really biased and inconsistent? Evidence on the
incidence of disciplinary sanction in the English Premier League. Journal
of the Royal Statistical Society, A, 170, 231-250.
NEAVE, N., & WOLFSON, S. (2003) Testosterone, territoriality, and the ‘home
advantage’. Physiology and Behavior, 78, 269-275.
NEVILL, A. M., BALMER, N. J., & WILLIAMS, A. M. (2002) The influence of
crowd noise and experience upon refereeing decisions in football.
Psychology of Sport and Exercise, 3, 261-272.
POLLARD, R. (2006a) Home advantage in soccer: variations in its magnitude
and a literature review of the inter-related factors associated with its
existence. Journal of Sport Behavior, 29, 169-189.
POLLARD, R. (2006b) Worldwide regional variations in home advantage
in association football. Journal of Sports Sciences, 24, 231-240.
SECKIN, A. (2006) Home advantage in association football: evidence from
Turkish Super League, Paper presented at ECOMOD conference in Hong
Kong, June 28-30, 2006.
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TABLE 1
MATCH PERFORMANCE TOTALS FOR HOME AND AWAY TEAMS IN
THE TURKISH SUPER LEAGUE, 2005-2006
Performance
indicator
Home Away Percent by
which home
exceeds away
t p d
Shots 4,321 3,420 26.3% 6.82 <.001 .63
Percentage of shots
resulting in goals
11.1% 11.3% -0.2% -0.19 .85 -.01
Percentage of shots
on target
40.1% 39.5% 0.2% 0.48 .63 .04
Passes to own team
in scoring zone
92,359 82,881 11.4% 4.54 <.001 .39
Tackles 5,344 5,251 1.8% 0.67 .51 .03
Fouls 4,363 4,278 2.0% 0.78 .44 .06
Yellow cards 598 644 -7.1% -1.49 .14 -.11
Red cards 37 47 -21.1% -1.09 .28 -.09
Ratio of cards to
fouls
.159 .177 -10.4% -1.72 .09 -.14
