ANALYSIS: METHODS AND USEFULLNESS

PREFACE

By this paper I wanted to answer to question, a banal question about its formulation, more and more hard about its answer: it is possible to measure a soccer match?

About its widest meaning, the measurment is the comparison between an object whose dimensions and properties are wellknown, and the what I want to know regarding its shape, dimensions or properties. In recent years, statistical concepts and tools have been introduced which attempt to respond to this need. However, I believe that today it is necessary not only to give tools but also to give the opportunity to build tools specifically taylor made to the specificity of a team or a season or a tactical principle to satisfy a request for knowledge. Thank these few rows, I re-built my university education, my professional skills in engineering and metrology,and my experience as video-analyst, for which I had to resort to concepts and tools that I thought were unrelated to soccer. By this I hope to provide useful and new methods for the exercise of the profession of video analyst.

Moreover the professional experience theached to me that well disegned procedures and methods can be more useful than expensive tools or high-priced structures.

THE COMPLICATION OF COMPLEX PHENOMENUM

The words complication and complexity are often applied as synonyms but, as usual for the words called synonymous, they distinguish their meaning thanks different values, everyone adjoints a particular feature that makes it different and unique

In order to understand th meaning of the two words and of the their derivatives it is useful rediscovering thier etymology.

Complexity is a noun whose own meaning derives from adjective complex, whose meaning derives from latin past participle “complexus” of “complecti” verb that means to weave together, to link. In this terms it is possible to see the scene of a group of object, or minds and ideas, that have been linked each other and that may not be untied now, or they may by barely unfastened. We can define complex everything is composed by many components whose boundaries are not easily distinguishble. We confer the feature “complex” to everything can be understood completely in a moment only but not during a long process composed by many steps everyone linked each other by a logical sequence of explanations in order to loosen doubts. A knot, once the tightest closing point is untied, then it opens very simply.

Complication means something provided by creases. A problem is complicated if its solution may be reached by a logical sequence of passes, everyone as consequence of previous. In this case the explanation is the process to "open the creases” that lets reach the solution of problem. In this case,an incisive image is the opening (“explanation”) of a rolled paper into a ball (“complicated problem”) that lets the reading what is written.

Thanks these meanings, it is evidedent that soccer is complex phenomenon. i.e. it is a set of complex phenomenons. Soccer may be understood enterely only or, may I be granted an unorthodox but impactful phrase, soccer may be understood thanks one stroke only. The journalistic locution “be able to read a soccer match” means the real capacity of comprehension of the phenomenon “match” during the carrying out, means the the whole comprehension of phenomenons which happen on the pitch and which define a precise dynamic of the play.

The football performance is the result to whom physical, psicological, relational, technical and tactical factors contribute; these factors may be observed on every single player, or on a team area, or on the whole team during a particular phase of match or during a particular period of match. In order to explain what it means “a particular period of the match”, I may allude to a typical example, as the teams which during the regular season are not able to keep the score and they conced a gol during the final minuts of the matches: tha numerical analysis may show the data that contribute to the decay of the soccer performance (distribution of player on pitch, rate of individual technical error, physical perforcamnce of player only … ); the task of first coach is the synthesis among the interpretative key that every member of the staff may develop. According this point of view, as it twill be debated in this written work, the process of analysis is antithetical than the process of synthesis.

According this approach, the complication becomes the process of the semplification of the complexity of the game. The translation into numbers of the phenomenon that occurs on pitch, supplies one of the possible description, or as well, one of the point of view of soccer phenomenon. A mistake to avoid is applying the numerical analysis as the unique interpretative key of the development of every soccer phenomenon on pitch. The numerical analysis supplies or corroborates a interpretative key of soccer phenomenon, allows to identify the wake points of performance in order to direct the work of entire team staff. At the same time the process of analysis may make understand some interpretative keys that leaded to the win. Moreover, during the regular season, a stable and well organised numerical elaboration of soccer performance allows to identify performance gaps between teams or performance gaps of the team during the season.

Thanks this approach, the numerical analysis shalle be used as an instrument to complicate that is the semplification of an objectively complex phenomenon in order to obtain some impartial points to improve the performance. Moreover the numerical analysis shall be the starting base for comprehension of the opposing teams, or the starting base of the performance changement in the long period; however numerical analysis cannot substitute the skills of the first trainer to distinguish the complexity of the soccer phenomenon.

ANALYSIS

The strange history of the soccer allowed this sport had been the last team sport to seek help from analytical methods constantly even if soccer is the team sport that needs, more than others sport, application of typical analytical methods. We know also history, even if it is strange, is due by precise and logical causes.

Unlike other team sport, the dynamics of soccer is not given by external rhythm and is not spaced: the game rules don’t impose times of game and they don’t impose precise spaces of game. For other team sport, as volley, basket and american football, during a specific phase of the match, the rhythm of game and the space of game are imposed by the rules. As shown in following chapters, the space and the rhythm are the two main criteria by which it is possible organising a process of analysis. In team sport in which the dynamics of game is divided in periods and spaces by specific rules, the application of a structured preocess of analysis is easier and more understandable.It is useful describing tangible exemples of the temporary and spatial dynamics of game in other team sport in order to compare the several analytical approach.

The basketball match is devided in 4 periods 12 minutes long each one, in other words, 4 periods 720 seconds long. Once the team gets the ball, it has 24 second to shot to basket. In case each team was able to use completely the time for the shot to basket, during a period 30 shots could be carried out, 120 shots during the whole match, 60 shot by each team. This simple exemple shows the structure of the game in a basket match supplies to the analyst the opportunity to divide match in many precise events. In basket the ball possession time is a data not much useful to the synthesis process because one of the main factor for the count of ball possession is not the capality of managing the ball by the team, but is the rule of game. Moreover this high number of specific events as shots on basket, approaching of possession ball, approaching of the game by the play, is a great source of data: we may compare a soccer match in which 40 shots to the goal post is a really uncommon data. Such a mass of data requires the application of statistical methods for processing such data.

At the same way we may compare another very popular sport in Italy, volley. A team shall score a point (match whore victory is awarded to the best of 5 sets), or rather a team shall carry out not less than 75 of attack schemes. Moreover the rules of volley impose the execution of 3 passes withaout any possibility of interception or contrast by the opponent. The quatity of passes in a soccer match is comparable to the quantity of passes in a volley passes, however, the types of passes are lower in a volley match which consequence is a great number of passes belonging to the same type as receptions and attaccks. Moreover in volley the separation of game spaces removes a variable regarding the managing of ball on pitch: during the managing of ball every player can decide own position without any relation to opponent players (in soccer this is the typical process to get away from the opponent marker).

The continuity of the game till long periods and the simultaneous sharing of the pitch by the two teams made soccer inert to an analytical approach during the history or at least difficult to implement and to understand. At the same time and for the same reasons, temporal continuity and spatial continuity make soccer the team sport that need the analytical approach more than other games. Now It is necessary to address the core issue round which the chapter is written.

The word “analysis” derives from ancient Greek “anàlysis” whose meaning is dissolution, and once again “anàlysis” derives from the verb analýo that means “take apart”. To initial problem it is mandatory to supply solution through the organization of a method of analysis through which to obtain raw data and on these to create indices of performance.

In a team staff, the match analyst shall carry out an really important job which limits and duties are defined by the meaning of the word “analysis”, that may be summarized by the following actions: divide, count and calculate.

This process shapes up to be as a measurment process, in other words as a process which resulti s the estimation of the value of a quantity. However this process shall be organized by:

·       objectives to obtain;

·       instruments to use;

·       methods and process of calculation;

·       methods for explanation of results.

These issues are all presented by following paragraphs.

THE USE OF ANALYSIS

In my opinion, In the world of sport definitions, structure and relation of the different types of analysis is not completely clarified among experts. The reason doesn’t dipend by the various viewpoints of experts only, but it dipends also by the technological resources which evolution allows new work approaches, the automation and integrations among the jobs.

A really clear example is shown by the development of videographic that allowed the creation of various file formats and the compilation of softwares which aim is the elaboration of the files. The introduciont of these instruments in the world of the sport allowed the develpment of the video analysis and the passing all technical difficulties in managing of video clips that, up to 80’s, was possible thanks to the films. The video analysis on the film, i.e. cutting and pasting without any possibilities of modification, was at that time, and it would be today, an unworkable job. In that period a notational approach already existed because software and calculation method for cumputer were available on the market. Anyway we may define 2 macro-disciplines (I may be granted the word): notational analysis (to which this article intends supply an operational contribution), and the video analysis. Today the video analysis software give the possibility to manage the tagging panels by which it is possible to to get quantitative data. This software is a fusion, maybe limited, of the macro-disciplines whose boundaries are not so clear in ths case. Today a pitch of evolution of the soccer analysis is the timing analysis, and in this case it is permitted by the evolution of video analysis softwares also.

The notational analysis is one of the tools to manage and measure performance capabilities of a team and, in the end, to improve a team in order to arrange a competition or, in the case of a long championship, to evaluate the game evolution during the championship. The meaning of the word “evaluate”, in this case, is properly the capability to define the value about the soccer performance. By this point of view the construction of an analysis model is one of the tools with which the staff shall equip itself to obtain the bigger quantity of useful data by which evaluate the soccer performance of the team.

The result of the analysis shall be used by the whole staff, first of all by the head coach. The quantity of data regarding the team that the head coach shall know are such that it is necessary to be able to provide in a coinciding and rapid way, by aggregate data, in other words, by indexes and, after that, by specific data. The concept “aggregate data” is common in other technical disciplines. The expression “aggregate data” means a data built up by the contribution of other data, everyone used by its specific weight. The aggregate data is the first level of analysis, i.e. the level that may give the first explanation of soccer phenomenon subject to analysis. The request of in-depth analysis imposes the dismemberment the first aggregate data, the performance index built up, into its fundamental components in order to distinguish the main contribution among the others, and at the same time the marginal one.

In generale the head coach shall carry out a constant summary job among the the works of the members of the staff. The summary is the process by the which the head coach take the decisions during the week or during a time period in which the activities are scheduled, or during the final minuts of a match, period featured by a great impredictability. Summary means the composition of the fact-finding contributions. Summary includes the idea of put together, and in this case put together the results of the skills of the staff members: for the analyst the production of numerical data is fundamental; data shall be well structured and they shall be able to describe the soccer phenomenon in progress. The results of these numbers are a part of elements by which the head coach reaches to the results of summary.

AIMS

The aims of analysis are the first step to manage a analysis system, but expecially to warrant its maintenance during the season. The word “maintenance” is generally extraneous to sport, but in this scope maintenance is the management and the constant revision of system aalysis during the season.

At the beginning of the season an agreement with the head coach about the method of work is necessary. Regarding the numerical part of the work, the agreement means establishing the parameters and indixes that must be constantly monitored for the team and possibly for the opposing teams.

During this preparatory phaseit is necessary the elaboration of a numerical system that may be rapresentative of the phenomenon that shall be analyzed. An example may clarify the concept.

During my job of analyst, the head coach asked to me a question. The team in that season had a high capacity about ball possession thanks to many forwards players provided by a good individual technical skill: these factors allowed the team to lead long offensive ball periods in opposite half pitch. Regarding this issue the request of the head coach was the evaluation of offensive skill of the team; the head coach used a journalistic expression that may be translated as “the capacity of drumming on offensive phase”. For this requirement, it was useful the IPO index, however IPO supplies the evaluation of effictiveness of offensive phase but it doesn’t supplies the method by which the teams can reach the IPO score: the same IPO score can be reach by teams that set an elaborated possession ball, or by teams that code offensive phases built by few and fast passes. In this case taylor made numerical parameters and indexes were necessary. The parameters were:

·       evaluation of the time period of possession in opposite half pitch (average, maximum, minimum, variation during the match, ect.)

·       quantity of passes during the attacks

·       definition of the features of passes during the attacks (author, pitch zones, types, etc.)

·       identification of event that ends the attack

The two first parameters are inappropriate about teams whose attacks are fast and are characterized by few passes, because they supply unuseful values for the analysis of performance.

During the regular season the analysis system can be modified because aims can be changed, i.e. some features of the game can be introduced or can be removed, and new parameters shall be setted. As written, the maintenance of analysis system means modification and control of numerical system in order to keep it congruent to the aims to reach. During the season a tactical changement, due by the change of come players or due by the change of aims of the teams, requires a changement of system analysis. The fundamental job of system analysis isn’t the production of numbers but the description the soccer phenomenon thanks the numbers. Every soccer phenomenon can be described by appropriate numbers. However we shall remember numbers cannot always supply the cause-and-effect relationship about a phenomenon, but numbers can supply the descriptions of many contemporary phenomenons.