Notational Analysis - The Applications of Notation

The Applications of Notation

Tactical evaluation The definition of tactical patterns of play in sports has been a profitable source of work for a number of researchers. The maturation of tactics can be analysed at different levels of development of a specific sport, usually by means of a cross-sectional design. The different tactics used at each level of development within a sport will inevitably depend upon technical development, physical maturation and other variables. The 'maturation models' have very important implications for coaching methods and directions at the different stages of development in each of the racket sports. These tactical 'norms' or 'models', based both upon technique and tactics, demonstrate how the different applications, defined above, can overlap.

Sanderson and Way (1977) used symbols to notate seventeen different strokes, as well as incorporating court plans for recording accurate positional information. The system took an estimated 5–8 hours of use and practise before an operator was sufficiently skilful to record a full match actually during the game. In an average squash match there are about 1000 shots, an analyst using this system will gather over 30 pages of data per match. Not only were the patterns of rally-ending shots (the Nth shot of the rally) examined in detail, but also those shots that preceded the end shot, (N-1) to a winner or error, and the shots that preceded those, (N-2) to a winner or error. In this way the rally ending patterns of play were analysed. Not surprisingly, processing the data for just one match could take as long as 40 hours of further work. The major emphasis of this system was on the gathering of information concerning `play patterns' as well as the comprehensive collection of descriptive match data. Sanderson felt that `suggestive' symbols were better than codes, being easier for the operator to learn and remember. The main disadvantages of this system, as with all longhand systems, was the time taken to learn the system and the large amounts of data generated, which in turn needed so much time to process it. The 1980s and 1990s saw researchers struggling to harness the developing technology to ease the problems inherent in gathering and interpreting large amounts of complex data. Hughes (1987) modified the method of Sanderson and Way so that the hand-notated data could be processed on a mainframe computer. Eventually, the manual method was modified so that a match could be notated in-match at courtside directly into a microcomputer. This work was then extended to examine the patterns of play of male squash players at recreational, county and elite levels, thus creating empirical models of performance, although the principles of data stabilisation were not thoroughly understood at the time. This form of empirical modelling of tactical profiles is fundamental to a large amount of the published work in notational analysis. By comparing the patterns of play of successful and unsuccessful teams or players in elite competitions, world cup competitions, for example, enables the definition of those performance indicators that differentiate between the two groups. This research template has been used in a number of sports to highlight the tactical parameters that determine success, and it has been extended in tennis to compare the patterns of play that are successful on the different surfaces on which the major tournaments are played. Most of the examples for tactical applications of notation could appear in the other sections of direct applications of notational analysis, but their initial aims were linked with analysis of tactics. The interesting theme that is emerging, from some of the recent research, is that the tactical models that are defined are changing with time, as players become fitter, stronger, faster, bigger (think of the changes in rugby union since professionalisation in 1996), and the equipment changes – for example, the rackets in all the sports have become lighter and more powerful. Over a period of less than 15 years the length of rallies in squash, for elite players, has decreased from about 20 shots, to about 12 shots per rally. An excellent review (Croucher, 1996) of the application of strategies using notational analysis of different sports outlines the problems, advantages and disadvantages associated with this function.

Technical evaluation To define quantitatively where technique fails or excels has very practical uses for coaches, in particular, and also for sports scientists aiming to analyse performance at different levels of development of athletes.

Winners and errors are powerful indicators of technical competence in racket sports and have often been used in research in notational analysis of net-wall games. It has been found that, for all standards of play in squash, if the winner: error ratio for a particular player in a match was greater than one, then that player usually won. (This was achieved with English scoring and a 19-inch tin). Although this ratio is a good index of technique, it would be better used with data for both players, and the ratios should not be simplified nor decimalised. Rally end distributions, winners and errors in the different position cells across the court, have often been used to define technical strengths and weaknesses. This use of these distributions as indicators is valid as long as the overall distribution of shots across the court is evenly balanced. This even distribution of shots rarely occurs in any net or wall game. Dispersions of winners and errors should be normalised with respect to the totals of shots from those cells. It would be more accurate to represent the winner, or error, frequency, from particular position cells, as a ratio to the total number of shots from those cells. Similarly, performance indicators such as shots are insufficient and need to be expressed with more detail, for example shot to goal ratios (soccer). Even these, powerful as they are, need to be viewed with caution and perhaps integrated with some measure of shooting opportunities? In rugby union, simple numbers of rucks and mauls won by teams may not give a clear impression of the match, the ratio of 'rucks won' to 'rucks initiated' is a more powerful measure of performance. This too could be improved by some measure of how quickly the ball was won in critical areas of the pitch? Many coaches seek the template of tactical play at the highest level for preparation and training of both elite players and/or teams, and also for those developing players who aspire to reach the highest position. Particular databases, aimed at specific individuals or teams, can also be used to prepare in anticipation of potential opponents for match play. This modelling of technical attainment has been replicated in many sports and form the basis of preparation at the highest levels by the sports science support teams.