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Introduction to football analytics 2021 - Complex Systems in ...
FOOTBALL ANALYTICS 2021
     THE ROLE OF CONTEXT IN TRANSFERRING
     ANALYTICS TO THE PITCH

12                                         Introduction
                                           to football
                                           analytics
                                           2021

     INTRODUCTION
Introduction to football analytics 2021 - Complex Systems in ...
FOOTBALL ANALYTICS 2021
THE ROLE OF CONTEXT IN TRANSFERRING
ANALYTICS TO THE PITCH

                                                                                   1: Complex Systems
— Angel Ric1,2, Sam Robertson3 & David                                             in Sport Research
Sumpter4,5                                                                         Group, Institut Nacional
                                                                                   d’Educació Física de

INTRODUCTION
                                                                                   Catalunya (INEFC),
                                                                                   Lleida, Spain
                                                                                   2: FC Barcelona
                                                                                   3: Victoria University,
The incorporation of new technology into sport has resulted in an increase in      Australia
both the volume of data and the variety of its types. This has led to a need for   4: Uppsala University
completely new areas of expertise (such as that provided by data analysts,         5: Hammarby IF
computer scientists and mathematicians) in organisational departments, as
well as adaptation by those already holding established roles, such as sport
scientists, strength and conditioning coaches and performance analysts. The
link between sports and computer sciences is now well established, and few
top-level professional structures resist its integration. However, despite the
interdisciplinarity of many staff teams, the knowledge and linguistic barriers
between different scientific fields mean that interaction between professionals
can often be difficult. One way to help address this problem is for experiential
and scientific knowledge, historically based on reductionism, to move towards
an understanding of sport as a complex phenomenon.

                                                                                                              13

The complexity of football lies mainly
in the number of interactions between
teammates and their environment, in
particular their opponents, but is also
found in the context of the game as a
whole. Traditionally, performance has
been evaluated by isolating system
components including the physical and
physiological; the technical (derived
from the players’ on-ball events); or
tactical aspects (the relationship between
teammates and opponents). These
“performance components” cannot
be seen at the same level but instead
in a nested way, because the inherent
processes within them emerge on
different timescales (figure 1). It is in
a competitive environment, evolving
over several years, where cooperative
processes are situated. The team
cooperates at the timescale of weeks
and months as well as more immediately
at the timescale of the match’s 90-plus
minutes to achieve the main objective
of winning. Interpersonal synergies
between players are then formed and
dissolved on a scale of seconds and tens
of seconds on the pitch, allowing them
to score a goal or avoid conceding (Ric et
al. 2016). These team patterns then make
the context for the individual actions that
emerge in a smaller timescale (seconds
or milliseconds). Therefore, context must
be understood as the environment for an
organism-environment relationship at all
scales and in performance analysis, from
seeing the team as an organism (Duarte
et al. 2012), through to the player himself
within the team, and even down to the
organs or systems within the athlete (Pol
et al. 2020).

INTRODUCTION
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     THE ROLE OF CONTEXT IN TRANSFERRING
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14

     Figure 1. Nested levels and scales of performance analysis.

     INTRODUCTION
Introduction to football analytics 2021 - Complex Systems in ...
FOOTBALL ANALYTICS 2021
THE ROLE OF CONTEXT IN TRANSFERRING
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For these levels of performance             et al. 2019), as well as the behaviour    have on mental or emotional pressure     15
analysis, tracking data (team), event       of the team’s performance in relation     (Bransen et al. 2019).
data (player) and biometric data            to the opponent’s disposition and the
(organ) is collected systematically.        ball (Fernández & Bornn, 2020). The       It is common for media and fans to
The integration of many of these            value of these behaviours (individual     consider players in a position within
data sets is essential and has              or collective) derives from the context   a system of play or team formation.
been recommended within clubs               in which they take place. For example,    However, within the same position(s),
or institutions for proper data             the value of actions-decisions with       different roles exist. Because of
management (Linke et al. 2018). FIFA,       or without a ball has been quantified     the dynamism of the game, these
in its aim to assist associate members      according to variables such as            positions are not static and depend
or other stakeholders, is developing        location, distance to the goal or the     on specific contexts that can be
standards for the unification of            angle, that vary in tens of second. On    identified within the game. Among
these data sources. Related to this,        the other hand, the effect of the style   them, moments in which a team has
the assignment of unique player             and system of play, or the number         the ball and others in which it tries
IDs aims to avoid duplication and           of players on each line of pressure       to recover it can be differentiated.
incompatibility between different           and defensive organisation, implies       Similarly, playing strategies such as
data sources and competitions, thus         contextual changes on a larger            pressure or withdrawal to recover
providing simplicity for joint data         scale of seconds or tens of seconds.      the ball or more elaborate direct play
analysis at all levels of performance.      Furthermore, changes in situational       when possessing the ball can also be
At a higher level, where performance        variables, already noted above, play an   identified (Castellano & Pic, 2019).
is affected by competition (e.g. the        important role in the effects they can
league), the effects of situational or
contextual variables on the behaviour
of players and teams should be
considered (Gómez et al. 2013).
In fact, during FIFA competitions,
performance can be affected by
macro-considerations such as the
location and climate of where the
competition takes place. However,
variables that influence at shorter time
scales (e.g. match location, half, score,
team formation, etc.) have also been
extensively studied. Traditionally, these
variables have been represented as
frequencies of individual actions or
aggregations of collective behaviour
derived from event and tracking data
respectively. However, this type of
analysis makes it difficult to consider
the context in the description of the
results. Consequently, recent statistical
models have emphasised estimating
the value of those actions (Decroos

INTRODUCTION
Introduction to football analytics 2021 - Complex Systems in ...
FOOTBALL ANALYTICS 2021
     THE ROLE OF CONTEXT IN TRANSFERRING
     ANALYTICS TO THE PITCH

16   Furthermore, the ball location             of the team that is in possession of      challenge for both data and sports
     between the different confrontation        the ball. So much so that FC Barcelona    scientists. This will be best achieved
     lines (Castellano et al. 2007) and         has been clearly differentiated from      through collaborative efforts.
     the depth of these lines will also         other teams (Gyarmati et al. 2014)
     determine more specific contexts of        because of how the team makes use         In summary, one of the challenges
     interaction. These structures can be       of it through passing, as an action by    for researchers and practitioners is
     practised and learnt over the time         which the players relate and interact.    to break down the linguistic barriers
     scale of months, but can change in the     Although the Barça style of play has      between the areas of knowledge or
     blink of an eye.                           been characterised by high passing        fields of science in order to allow
                                                percentages, this is not an end in        better and more efficient information
     Identifying the most common                itself, but a means through which the     transmission. The adoption of a
     formations during these game               players organise themselves around        transdisciplinary theoretical approach
     contests, and the changes derived          the ball.                                 will allow a better understanding of
     from the transitions between them,                                                   all scales of the emergent processes
     are some of the challenges that some       It is precisely this organisation that    arising from football environments
     researchers are already beginning          defines one of the most common            (e.g. talent identification and
     to address. The stability of these         drills during the club’s team training    development, performance analysis,
     formations, and also derived from          sessions, the “rondo”. Despite the        injury risk assessment, etc.). The
     the values of width and depth of           extensive research on the use of          identification of essential variables
     the team, dispersion of the players        small-sided games (Clemente et al.        through current analytical techniques
     respect to their team centroid and the     2020), the effects from rondos or         (e.g. machine learning) from the
     depth of the rear line, characterise its   other common training drills such         inductive approach would allow the
     organisation. In turn, this definition     as positional games (Casamichana          modelling of simulations derived
     makes possible to characterise             Gómez et al. 2018) on player behaviour    from those variables (deductive
     defensive disruption as a function         or the dynamics of the coordination       approach) to capture the system’s
     of the variation from the previous         between them are still unknown.           performance/intelligence (Hristovski &
     set of variables, allowing players’        Little research has addressed the         Balagué, 2020). The conceptualisation,
     performance to be classified according     need to identify values, parameters       quantification and modelling, through
     to the impact that their passes have       or patterns of play that allow the        entropy, could one day elucidate a
     on the opponent’s defensive (dis)          design of training scenarios that are     paradigm shift in sports performance
     organisation (Goes et al. 2019).           representative of the game. There are     that might allow its unification at
     Most football teams are organised          already some publications which,          all levels of analysis. Under the
     according to the location of the goals,    through the identification of physical    nested relationship between levels,
     because of two main objectives: to         demands (e.g. distance covered)           the context-dependent analysis of
     score a goal and protect their own         according to the game context,            performance will be presented in the
     goal. However, the location of the         help to design drills that fit with the   following chapters by offering to the
     ball is essential to define the context    identified demands (Bradley & Ade,        reader a wide view of the research
     of the game and, in some cases, it         2018). However, making training           carried out by some of the most
     is the element that determines the         drills that meet not only physical but    renowned experts from that topic.
     organisation of the players, regardless    also behavioural demands is still a

     INTRODUCTION
Introduction to football analytics 2021 - Complex Systems in ...
FOOTBALL ANALYTICS 2021
THE ROLE OF CONTEXT IN TRANSFERRING
ANALYTICS TO THE PITCH

REFERENCES

Bradley, P. S., & Ade,    Probabilistic Model of     nisms: Implications      org/10.4324/978020         Psychology, 7. https://
J. D. (2018). Are         the Development of         of Sociobiological       3806913                    doi.org/10.3389/          17
Current Physical          Play in Soccer. Quality    Models of Behaviour                                 fpsyg.2016.01513
                                                                              Gyarmati, L., Kwak, H.,
Match Performance         and Quantity, 41(1),       for Research and
                                                                              & Rodriguez, P. (2014).
Metrics in Elite Soccer   93–104. https://doi.       Practice in Team
                                                                              Searching for a Uni-
Fit for Purpose or is     org/10.1007/s11135-        Sports Performance
                                                                              que Style in Soccer.
the Adoption of an        005-3148-0                 Analysis. Sports
                                                                              2014 KDD Workshop
Integrated Approach                                  Medicine, 42(8),
                          Castellano, J., & Pic,                              on Large-Scale
Needed? International                                633–642. https://doi.
                          M. (2019). Identifica-                              Sports Analytics.
Journal of Sports                                    org/10.2165/
                          tion and Preference                                 arxiv:1409.0308
Physiology and                                       11632450-
Performance, 13(5),       of Game Styles in          000000000-00000          Hristovski, R., &
656–664. https://         LaLiga Associated                                   Balagué, N. (2020).
                          with Match Outco-          Fernández, J., &
doi.org/10.1123/                                                              Theory of Cooperati-
                          mes. International         Bornn, L. (2020).
ijspp.2017-0433                                                               ve-Competitive Inte-
                          Journal of Environ-        SoccerMap: A Deep
                                                                              lligence: Principles,
Bransen, L., Robbere-     mental Research and        Learning Architecture
                                                                              Research Directions,
chts, Pi., Van Haaren,    Public Health, 16(24),     for Visually-Inter-
                                                                              and Applications.
J., & Davis, J. (2019).   5090. https://doi.         pretable Analysis in
                                                                              Frontiers in Psycholo-
Choke or Shine?           org/10.3390/ijer-          Soccer. Proceedings
                                                                              gy, 11, 2220. https://
Quantifying Soccer        ph16245090                 of the 2020 European
                                                                              doi.org/10.3389/
Players’ Abilities                                   Conference on Machi-
                          Clemente, F. M.,                                    fpsyg.2020.02220
to Perform Under                                     ne Learning and Prin-
Mental Pressure.          Afonso, J., Castillo,      ciples and Practice of   Linke, D., Link, D.,
Proceedings of the        D., Arcos, A. L., Silva,   Knowledge Discovery      & Lames, M. (2018).
13th MIT Sloan Sports     A. F., & Sarmento, H.      in Databases, 1–16.      Validation of Elec-
Analytics Conference,     (2020). The effects        https://bitbucket.org/   tronic Performance
1–25. http://www.         of Small-Sided             ghentdatascience/        and Tracking Systems
sloansportsconferen-      Soccer Games on            ecmlpkdd20-papers/       (EPTS) Under Field
ce.com/wp-content/        Tactical Behavior and      raw/master/ADS/          Conditions. PLoS ONE,
uploads/2019/02/          Collective Dynamics:       sub_1006.pdf             13(7). https://doi.
Choke-or-Shi-             A Systematic Review.                                org/10.1371/journal.
                          Chaos, Solitons and        Goes, F. R., Kempe,
ne-Quantifying-Soc-                                                           pone.0199519
                          Fractals. https://         M., Meerhoff, L. A., &
cer-Players-Abili-
                          doi.org/10.1016/j.         Lemmink, K. A. P. M.     Pol, R., Balagué, N.,
ties-to-Perform-Un-
                          chaos.2020.109710          (2019). Not Every Pass   Ric, A., Torrents, C.,
der-Mental-Pressure.
                                                     Can Be an Assist: A      Kiely, J., & Hristovski,
pdf                       Decroos, T., Van           Data-Driven Model to     R. (2020). Training or
Casamichana Gómez,        Haaren, J., Bransen,       Measure Pass Effecti-    Synergizing? Complex
D., Gómez Diaz, A.,       L., & Davis, J. (2019).    veness in Professional   Systems Principles
Cos Morera, F., & Mar-    Actions Speak Louder       Soccer Matches. Big      Change the Unders-
tín García, A. (2018).    Than Goals: Valuing        Data, 7(1), 57–70. ht-   tanding of Sport
Wildcard Players          Player Actions in          tps://doi.org/10.1089/   Processes. Sports
During Positional Ga-     Soccer. Proceedings        big.2018.0067            Medicine - Open,
mes. Apunts. Educa-       of the ACM SIGKDD                                   6(1), 1–13. https://doi.
                          International Confe-       Gómez, M. Á.,
cion Fisica y Deportes,                                                       org/10.1186/s40798-
                          rence on Knowledge         Lago-Peñas, C., &
133, 85–97. https://                                                          020-00256-9
                          Discovery and Data         Pollard, R. (2013).
doi.org/10.5672/
                          Mining. https://doi.       Situational Variables.   Ric, A., Torrents,
apunts.2014-0983.
                          org/10.1145/329250         In T. McGarry, P.        C., Gonçalves, B.,
es.(2018/3).133.06
                          0.3330758                  O’Donoghue, & J.         Sampaio, J., &
Castellano, J.,                                      Sampaio (Eds.),          Hristovski, R. (2016).
Hernández-Mendo,          Duarte, R., Arajo, D.,     Routledge Handbook       Soft-Assembled
A., Morales-Sánchez,      Correia, V., & Davids,     of Sports Perfor-        Multilevel Dynamics
V., & Anguera, M. T.      K. (2012). Sports          mance Analysis (pp.      of Tactical Behaviors
(2007). Optimising a      Teams as Superorga-        277–287). https://doi.   in Soccer. Frontiers in

INTRODUCTION
Introduction to football analytics 2021 - Complex Systems in ...
FOOTBALL ANALYTICS 2021
     THE ROLE OF CONTEXT IN TRANSFERRING
     ANALYTICS TO THE PITCH

18                                         Always
                                           think before
                                           computing!

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— Rafel Pol1,2 & Natàlia Balagué3                                              1: Real Federación
                                                                               Española de Fútbol
                                                                               (RFEF)

INTRODUCTION
                                                                               2: Complex Systems
                                                                               in Sport Research
                                                                               Group, Institut Nacional
                                                                               d’Educació Física de
                                                                               Catalunya (INEFC),
What could we tell analysts to help them better connect theory and practice?   University of Lleida,
Let’s start from the beginning: why do we analyse the game?                    Spain
                                                                               3: Complex Systems
                                                                               in Sport Research
                                                                               Group, Institut Nacional
                                                                               d’Educació Física de
                                                                               Catalunya (INEFC),
                                                                               University of Barcelona,
                                                                               Spain

                                                                                                          19

R: There are three types of analysis that
practically all professional clubs apply
today. The first is oriented toward the
scouting of talented players that the
club may want to sign. This entails
analysing the market to gain insight and
decide whether or not players might be
an attractive choice for certain positions.
The second is analysis of opponents
(teams or players), which is aimed at
understanding the characteristics and
weaknesses of rivals to prepare for
competition against them. The third is
player performance analysis, which is
currently focused on kinematic variables
(e.g. total distance covered, velocity,
etc.). I am not aware of any elite club in
the world that does not use this level of
analysis.

N: This means that there are three
organisational levels (club, team
and player) that are involved in such
performance analysis. Any decision
made at a higher level (club), such as
signing new players, affect those made
at lower levels (e.g. team strategies,
players actions) and vice versa. That
is, the composition of the roster will
impact playing systems and competitive
strategies, which, in turn, bind the
performance and actions of individual
players (Balagué et al. 2019); Pol et al.
2020). Likewise, lower-level events
(e.g. an injured or underperforming
player) shape higher-level ones (change
of playing strategies, signing of new
players). It is important to take into
account that these three levels cannot

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20

     be understood in isolation when              skilled dribbler may be invaluable in        she won’t just lose her/his reputation
     thinking about performance analysis.         a team that covers a lot of distance         as the best centre-back but will come
                                                  due to its playing style. However, if we     off as a shoddy defender. In contrast,
     R: In fact, these three levels share a       put that same player in a team that          consider a fast and small centre-back,
     common limitation, inherited from            spends a lot of time in possession of        such as Javier Mascherano, who
     an overly reductionist brand of sports       the ball and that generally forces the       played with Barça. In the context of
     science: they underestimate context.         opponent to retreat, s/he will lose          that team, he was undoubtedly one
                                                  that running space and, suddenly,            of the best centre-backs in the world.
     a. Club level: When signing players,         no longer seem like such a skilled           However, he probably would have
        we often forget that some of them         dribbler. Likewise, we might say that a      had more difficulty performing at
        perform better in certain clubs           player is the best centre-back without       that level had he been on a team that
        and worse in others. Big data and         specifying that his or her team plays        played defence closer to its own goal.
        statistics are used to confirm that a     close to its own goal, leaving little        In fact, when playing with Argentina,
        player is good at performing certain      space behind them. This player might         which does indeed play defence
        actions; it is then inferred that s/he    be very good at confrontation but            closer to their own goal, he was more
        will perform other actions equally        might not be a very fast runner. If s/       of a midfielder than a centre-back.
        well. But we must also examine the        he is signed by a team that plays            Players who are deemed the best in
        context in which s/he is performing       in possession of the ball in the             their position may end up seeming
        these actions exceptionally well.         opponent’s half, s/he will be forced         second-rate when the context is
        There are also other areas outside        to run long distances, face multiple         changed.
        the context of the match that allow       players at once in a larger space and
                                                                                             b. Team: When analysing an opponent,
        us to predict whether or not a player     enjoy fewer one-on-one challenges
                                                                                                there is a general tendency to make
        will adapt well to the club. A fast and   in her/his territory. As a result, he or
                                                                                                statements such as “this team usually

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  presses in this way” or “they play          quantification is very uninformative. For    We can gather a great deal of                 21
  with the ball like this”. The idea is       example, the simplest way to objectify       information through conversations
  to offer an average, or a general           perceived exertion (PE) is with the Borg     with athletes about how they feel in
  rule, of how the team plays. But            scale (RPE 6-20 or CR-10) (Borg, 1998).      similar situations. This also may help
  “this is how they press” can only be        Based on my experience in different          the player become more aware of her/
  confirmed when the opponent does            situations and with different teams, the     his condition and learn to express it as
  not force them to play differently.         information obtained from PE ratings         a comparison to her/himself and not
  For example, this statement will            means very little if the players do not      to an external scale. But I think that if I
  no longer hold true when playing            value this type of monitoring and if it is   wanted to publish these data I would
  against a team with the resources           not adequately contextualised. We must       be required to quantify them based
  to resist such pressure. Identifying        encourage and harness athletes’ ability      on an external universal reference
  an “average” or a “summary” in this         to perceive and integrate information        to objectify the differences between
  way does not provide information            and put it at the service of monitoring.     performance on different days and
  about what a team will do in a              These are exceptional means of injury        across different weeks. That would
  context in which their standard             prevention and promote autonomy and          be difficult to publish, don’t you think,
  playing style is no longer effective.       self-management of workloads (Pol et         Natalia?
  This analysis, therefore, becomes           al. 2018).
  useless if, as a team, we manage
  to overcome our rival. And since
  that is the general objective, it is
  useless all around. Nevertheless,
  averages are compiled for teams
  to identify their characteristics and
  label them, despite the fact that these
  characteristics will disappear as soon
  as the context of the game changes.
c. Player: When analysing the
   performance of individual players, we
   once again seek out these averages
   and compare them with the team
   average, sometimes with the player
   averages and sometimes with what
   is typical in that level of competition.
   These averages offer little information
   about whether or not a player is
   capable of adapting to the demands
   arising from the context of the match.
At all three levels of analysis there is an
attempt to extract quantitative data and
little emphasis on the context.

Absolute, decontextualised

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22

     N: Right, sports sciences place a           depending on the context. Since            Changing Perspectives in Sport
     greater emphasis on quantitative            every competition and every rival          Performance,” (Balagué y Torrents,
     research, easier to objectify, and relies   is different, it would be a mistake        2005). It might be useful to look
     too heavily on group data averages.         to compare kinematic information,          back on its message to clarify what
                                                 obtained either at individual or           it means performance analysis from
     However, it is possible to                  collective level, without an adequate      a complex perspective. Certain study
     operationalise psychological or             contextualisation and interpretation.      variables such as entropy, big data or
     sociological information extracted          In this sense, examining the dynamics      more advanced processing techniques
     from interviews and focus on                of change of the variables under           (e.g. deep learning) are generally
     individual data obtained from time          study is more informative to recognise     associated with the analysis of the
     series (Molenaar, 2004; Nesselroade         whether performance stagnation or          game as a complex phenomenon.
     and Molenaar, 2010: Rose et al. 2013).      deterioration is taking place. This is     However, processing large volumes
     The main experimental model used            applicable to all the aforementioned       of data and variables compiled from
     to test research hypotheses in sports       levels and requires updated                these techniques is of little use if
     sciences is the comparison of group         assumptions and deep theoretical           there is not accompanied by a deep
     data means through inferential              understanding of the examined              understanding of the process under
     statistics. The fact that the averages      processes.                                 study. It must also be noted that
     obtained do not correspond to any                                                      merely processing common variables
     specific individual is generally not        R: Most clubs have entire departments      in the study of complex systems does
     taken into account when interpreting        devoted to generating analysis tools       not necessarily mean that a complex
     and applying research results. In fact,     that, in practice, add no value to the     analysis of the game is performed.
     neglecting the idiosyncrasy of the          work of the coaches. The problem           For example, the entropy measures,
     structure of time-dependent variations      lies in developing applications or         usually associated with the study
     within a single individual and              reports without first thinking about the   of complex systems, can be used
     assuming the equivalence between            underlying theoretical assumptions.        to answer a very simple question
     inter- and intra-individual variability     If the phenomena to be analysed are        about cause and effect relationships
     is a common mistake of this type            not properly understood, it is difficult   that has nothing to do with a
     of research that leads to erroneous         to create effective applications. The      complex perspective. Essentially,
     interpretations and inadequate              first thing to do is to improve our        in this perspective, we are not just
     practical applications (Rose, 2016,         understanding about the principles         changing the type of data analysis
     Balagué et al. in press).                   that lead the behaviour of the systems     or study variables but the type of
                                                 we deal with: the game, the team,          questions, assumptions and research
     Ignoring the context in which complex       the players. Only then a right answer      interpretations. This is something we
     adaptive systems interact can be very       to the question “what do we need to        need to emphasise so that resources
     misleading. In particular, when such        analyse?” will emerge. With the current    are not wasted. Otherwise, the same
     context is non-stationary and fast          approach, countless resources are          mistake will be made over and
     changing, as during sports games. For       being wasted.                              over, just with more sophisticated
     example, the total distance covered                                                    technology and more data or new
     by a player or her/his running velocity     N: Years ago, we published an article      variables, but still without improving
     may be functional or un-functional          titled “Thinking Before Computing:         the understanding of the phenomena

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                                             Statistics itself, which
                                                does have clear
                                             limitations, is not the
                                                 main problem

                                                                                                                              23

under study.                                effects (Amrhein et al. 2019). Even      main problem. It is the misuse and
                                            the American Statistical Association     misinterpretation of statistics in an
R: In fact, this lack of reasoning is       has spoken out against the misuse        oversimplified research context. There
more common in science than you             of inferential statistics and its role   is a general belief that exceeding a
might think. The journal Nature             in promoting erroneous and biased        threshold for statistical significance
recently published an article               findings (Wasserstein et al. 2016;       means a result is real (Wasserstein
signed by 850 scholars of different         McShane et al. 2019). This tendency is   et al. 2016; Amrhein et al. 2019,
academic ranks that denounces               not exclusive to performance analysis,   McShane et al. 2019). Without a deep
the misuse of statistics in research.       but pervasive throughout sports          understanding of the assumptions
Specifically, it calls for the retirement   science.                                 behind the research hypotheses,
of statistical significance to put                                                   methodological decisions, data
an end to publications that report          N: Statistics itself, which does         analysis and interpretation, the
“hyped” results and dismiss crucial         have clear limitations, is not the       research is no longer practical but

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     ANALYTICS TO THE PITCH

     rather may add to the confusion and        that merely creating multidisciplinary        to the concept of constraints but to all
24
     harm the advance of knowledge. If          teams will not overcome the obstacles         the DST concepts; valid for all levels of
     we do not understand the theory,           of studying a phenomenon that                 analysis (see Fig. 1).
     we cannot propose useful practical         belongs to no specific discipline:
     applications. We need to be aware          neither the game nor the player fit           However, despite having powerful
     of the norm in sports science:             within these disciplines. Therefore,          tools such as Dynamic Systems Theory,
     isolating variables, comparing             it is not just about adding new               it is quite challenging to evaluate the
     group averages, obtaining results          professionals and perspectives from           dynamics of change in collaborative
     based on statistical significance          different branches, but about sharing         and competitive processes in which
     and putting them into practice as          a common approach to how the                  rivals never behave in exactly the
     general truths. All this represents a      systems that we work with function            same way and there are no static
     significant bias for the advancement       – whether players or teams – and              situations, as in football.
     of knowledge. The reductionist             making contributions from that
     tendency, inherited from medicine          common vision.                                R: Perhaps we should change the
     and psychology, and over-simplified                                                      type of question or the objective of
     theoretical assumptions limit the          N: Right, there are transdisciplinary         performance analysis. If we have a
     evolution of our understanding of          initiatives that pursue real knowledge        deep understanding of the dynamic
     complex phenomena linked to sports         integration, but multidisciplinarity          mechanisms of players/teams to
     performance.                               is in fact non integrative (Balagué           adapt to the context of a match or
                                                et al. 2017). It is necessary to clarify      training session, and develop them
     It is possible, however, to turn           what a real integration means, and            during training sessions, we could
     away from tradition and opt for            which type of approaches may                  even forget about analysing the
     other models, such as those of             satisfy it. Some authors suggest that         opponent. The issue is that training
     complex systems, widely applied            training-methodology departments              sessions are often focused on the rival,
     in several emerging branches of            should integrate knowledge on the             on their weaknesses and strengths as
     biology. Of course, this option does       basis of an ecological dynamics               detected from analysing their game.
     mean overcoming the resistance             approach (Rothwell et al. 2020). This         In response, optimal, predetermined
     and difficulties that come with any        perspective, however, focuses on              solutions are prepared. But if we
     paradigm shift. We now find ourselves      the level of perception and action,           changed the objective from having
     in the midst of that transition, forcing   while neglecting other relevant               the team or player learn specific
     models that are to some extent             levels related to strength and                solutions to improving their potential
     incompatible to coexist. However,          conditioning (e.g., biochemical and           for adaptation and diversity (Pol et
     the difficulties associated with such      physiological). In line with trans- or        al. 2020) and their ability to resolve
     paradigm shifts should not discourage      cross-disciplinarity, some authors            unpredictable situations – such as
     the pioneers because they are on the       sustain that integration requires a           those that happen regardless of how
     right track. Interdisciplinary work is     common scientific vocabulary shared           we train – we would not even need to
     being encouraged in many scientific        across disciplines (Balagué et al. 2017);     analyse the opponent or, at least, not
     branches and the contributions of          Hristovski et al. 2017). In this direction,   in the way we currently do. We could
     physicists, mathematicians and             Glazier (2017) proposes the unification       focus instead on analysing the state
     computer scientists, collaborating         of knowledge based on the concept of          of our team and deciding whether
     with sports scientists, are key in         constraints and Balagué et al. (2017)         we should generate new training
     performance analysis.                      suggest the Dynamic Systems Theory            challenges or a sense of confidence by
                                                as an ideal integrative framework. DST        strengthening scenarios already under
     R: However, it is important to highlight   does not limit the common vocabulary          control. But, of course, for that we

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would need the deep understanding         that is not accustomed to competing
                                                                                                                         25
of the theoretical foundations of         at a high frequency qualifies for a
performance that we mentioned             European competition, is that the
earlier.                                  coaches underestimate that they
                                          can no longer train as much as they
N: Even separating training and           used to. If they do not address the
competition would no longer make          process as a whole, understand that
sense. There is training in competition   competition is part of the process,
and competition in training, so           and eliminate a significant part of the
why shouldn’t we view them as             training, they end up overwhelming
continuous, adaptive processes with       the team. Even if the coach is
disturbances and constraints that are     changed, it becomes very difficult to
more or less intense and/or global?       revive the team. This situation repeats
                                          itself every year.                        Figure 1.
R: In fact, training while competing is                                             Structure and organisation of
the best type of training; this becomes   N: There is a fundamental problem         scientific fields sharing the same
                                                                                    concepts and principles from Dyna-
very clear in teams that play every       in our understanding about the            mic Systems Theory.
three days. One of the main problems      systems we deal with: it is generally     v
that usually crop up after a team         assumed that they are dominated by

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     THE ROLE OF CONTEXT IN TRANSFERRING
     ANALYTICS TO THE PITCH

                                                   More information
                                                  does not mean more
                                                      knowledge

26   the dynamics of their components,         put into question. These common           For example, specialisation does not
     instead of being dominated by the         and artificially built barriers can be    encompass the fact that the levels
     dynamics of the interactions among        reduced under the proposed paradigm       of analysis previously mentioned
     such components, as occurs in             shift, and specifically, under the        – club, team and player – do not
     complex systems (Delignières and          umbrella offered by the Dynamic           exist independently of each other
     Marmelat, 2012). This explains why        Systems Theory.                           but are related by circular causality
     training focuses on components and                                                  (Balagué et al. 2019). In cooperative
     underestimates the counterproductive      R: The key to knowledge integration       and competitive environments,
     effects this may have on competition.     is a shared understanding of the          maintaining and developing the
     For example, fragmenting and              phenomenon to be studied. You can         potential for functional diversity/
     stabilising excessively positional play   have a team comprising professionals      unpredictability – also defined as
     in attack and defence (separately)        from different disciplines working        intelligent cooperative-competitive
     during trainings may harm the             on an integrated job, but if the          behaviour – at different levels is
     transitions during competitions.          biomechanist tells you that a player      crucial (Hristovski and Balagué,
     Moreover, there is a crucial              missed a pass because s/he shot from      2020). In other words, having a
     training goal in team sports that         the wrong angle, while the physical       smart club, a smart team, and smart
     is often underestimated by this           trainer says that s/he was worn out       players means evading and escaping
     component-dominant approach:              by the end of the game because s/he       situations of reduced possibilities of
     developing interpersonal synergies        played for too many minutes and did       goal achievement in different contexts.
     among players. These synergies,           not rest enough, and the physiologist     Opponents try to reduce that diversity
     which are the basis of the team’s         agrees with the physical trainer and      potential intervening at all levels, and
     functional diversity potential and        adds that the results of the last blood   the goal is to maintain and develop it
     competitiveness (Pol et al. 2020),        analysis were not good enough, what       despite these disruptions. Functional
     require collective challenges and         do you do? You say you are doing          players are those that contribute to
     constant interaction between              multidisciplinary and integrated work     the collective goal, and functional
     players to overcome them. If training     because every specialist provides         teams are those that escape and
     objectives change their focus, the line   their view on the phenomenon, but         quickly regain the diversity potential
     between training and competition will     if all these specialists understand it    despite their opponents’ actions. One
     be blurred. Technology must serve         differently, and look at it from their    fundamental advantage is that this
     that understanding, not the other way     own perspective, it becomes very          potential can be measured using a
     around. Different departments of the      difficult to generate new knowledge.      common variable: information entropy.
     club, even members of the coaching        In such cases, a multidisciplinary team
     staff, often analyse competition          is of little or no use and may even       R: In conclusion, to improve the
     and training separately. That is, the     detract from the work. If we do not       methodologies of game analysis
     performance department and the            change our understanding, any other       we must start by improving our
     physical trainers focus on analysing      efforts we make are useless.              understanding of the phenomena
     players and their physical and                                                      under study. When our understanding
     physiological response during training    N: More information does not              changes, the questions we ask
     through GPS data, and analysis            mean more knowledge. Scientific           ourselves change; and when the
     departments focus on the competition      specialisation has provided a lot         questions change, the way we analyse
     (event data and movement tracking)        of detailed information, but this         phenomena necessarily changes as
     through video analysis. Perhaps           does not necessarily imply greater        well.
     this fragmentation should also be         comprehension and knowledge.

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FOOTBALL ANALYTICS 2021
THE ROLE OF CONTEXT IN TRANSFERRING
ANALYTICS TO THE PITCH

REFERENCES

Amrhein, V., Green-          CritRevBiome-               with P-Technique
land, S., & McShane, B.      dEng.2013006727             Factor Analysis and          27
(2019). Scientists Rise                                  the Idiographic Filter.
                             Glazier P. (2017).
Up Against Statistical                                   Behavior Genetics,
                             Towards a Grand
Significance. Nature,                                    40(6), 776-783.
                             Unifying Theory of
567, 305-307. https://
                             Sports Performance.         Rose, T. (2016). The
doi.org/10.1038/
                             Hum. Mov. Sci.,             End of Average: How
d41586-019-00857-9
                             56:139–56. https://         to Succeed In a World
Balagué, N. y Torrents,      doi.org/10.1016/j.          That Values Sameness.
C. (2005). Thinking          humov.2015.08.001           USA: HarperCollins
Before Computing:
                             Hristovski, R., Aceski,     Rothwell, M., Davids,
Changing Perspectives
                             A., Balagué, N., Seifert,   K., Stone, J. A., O’Sulli-
in Sport Performance.
                             L., Tufekcievski, A.,       van, M., Vaughan, J.,
International Journal
                             Aguirre, C. (2017).         Newcombe, D.J., Shu-
of Computer Science in
                             Structure and Dy-           ttleworth, R. (2020). A
Sport, 4, 2, 5-13.
                             namics of European          Department of Metho-
Balagué, N., Torrents,       Sports Science Textual      dology Can Coordinate
C., Hristovski, R., Kelso,   Contents: Analysis          Transdisciplinary
JAS. (2017). Sport           Of ECSS Abstracts           Sport Science Support.
Science Integration:         (1996–2014). European       Journal of Expertise, 3,
An Evolutionary              Journal of Sport Scien-     1, 55-65. http://shura.
Synthesis. European          ce, 17, 1, 19-29. http://   shu.ac.uk/25980/
Journal of Sport Scien-      dx.doi.org/10.1080/174
                                                         Wasserstein, R. L., &
ce, 17, 1, 51-62. https://   61391.2016.1207709
                                                         Lazar, N. A. (2016).
doi.org/10.1080/17461
                             Hristovski, R., Balagué,    The ASA’s Statement
391.2016.1198422
                             N. (2020) Theory of         on p-Values: Context,
Balagué, N., Pol, R.,        Cooperative-Com-            Process, and Purpose.
Hristovski, R., Torrents,    petitive Intelligence:      American Statistician,
C., Ric, A. (2019). On       Principles, Research        70(2), 129-133. https://
The Relatedness and          Directions and Appli-       doi.org/10.1080/00031
Nestedness of Cons-          cations. Frontiers in       305.2016.1154108
traints. Sports Medici-      Psychology, 11. https://
ne Open, 5, 6. https://      doi.org/10.3389/
doi.org/10.1186/             fpsyg.2020.02220
s40798-019-0178-z
                             McShane, B. B., Gal, D.,
Balagué, N., Hristovski,     Gelman, A., Robert, C.,
R., Almarcha, M. C.,         & Tackett, J. L. (2019).
García-Retortillo, S.,       Abandon Statistical
Ivanov, P. (in press)        Significance. American
Network Physiology           Statistician, 73(sup1),
of Exercise: Vision and      235–245. https://doi.or
Perspectives. Frontiers      g/10.1080/00031305.2
in Physiology.               018.1527253).
Borg, G. A. (1998).          Molenaar, P. C. (2004).
Borg’s Perceived             A Manifesto on Psy-
Exertion and Pain Sca-       chology as Idiographic
les. Champaign (IL):         Science: Bringing
Human Kinetics.              the Person Back Into
                             Scientific Psychology,
Delignieres, D., and
                             This Time Forever.
Marmelat, V. (2012).
                             Measurement, 2(4):
Fractal Fluctuations
                             201-218.
and Complexity:
Current Debates and          Nesselroade, J. R.,
Future Challenges.           Molenaar, P. C. (2010).
Crit. Rev. Biomed. Eng.      Analyzing Intra-Per-
40, 485–500. https://        son Variation: Hybri-
doi.org/10.1615/             dizing the ACE Model

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