Sharp (1997) described squash as one of the most dynamic and physical games played. Squash is a sport that is fiercely contested between two players inside a four walled court. Where, the performance and actions of one player consequently influences the actions of the other. Pearson, (2001) found that it is imperative to maintain pressure on the opponent by not letting them gaining authority of the middle of the court, which is often called the ‘T’ zone. However, McGarry et al (1998) found that the rhythm and intensity of a game can alternate between stable and unstable behaviours. If an interruption occurs to a steady state of play it can be identified as a perturbation, and can be used to provide valuable data related to winning performances (Hodges et al 1998). Hughes and Reed, (2005) agreed, and further stated that a “perturbation exists when the normal rhythm is interrupted by high and low skill, which consequently results in a particular outcome”. Perturbations do occur in most sports that have a rhythmical pattern but to recognise them, can be difficult for the analyst as what one person may see as a perturbation, another may not.

McGarry et al (1999) studied perturbations in squash and illustrated that perturbations may result from a good shot that extends the opponent, or a loose shot which opens up a gap on the court allowing the opponent to capitalise on the mistake. McGarry et al (1999) also carried out an experiment to identify whether elite and non elite squash players could identify perturbations in a squash match. The first experiment included six experts and six novices, in which they all watched sixty rallies each. The results produced to show where and in what rally they thought the perturbation occurred. The results showed good inter- rater agreement for each subject.

The reason for investigating this specific topic area is that by analysing perturbation attempts it allows to extract further strengths and weaknesses of the two players which will enable to create performance profiles to enhance performances. With the game becoming more and more aggressive and the scoring changing to point per rally it is highly likely that perturbation attempts will occur more often. Also as the technology is advancing, analysis is becoming more of an influential tool, as players and coaches are being updated with more research ideas. Murray and Hughes, (2001) said that “by using tactical performance profiles to pull out and visualise these critical aspects of performance, players can build justified and sophisticated tactical plans.”

Perturbations can be coded through a hand notation system and presented in a quantitative format. For many years, feedback given to the players that is presented quantitatively, the more positive affect it has on their performances (Franks, Goodman and Millar, 1983). Notational analysis is renowned as a very important factor in the development of sporting athletes. Notational Analysis of sport provides us with the ideal tool to collect this objective performance data (Murray and Hughes 2001). Notational analysis in squash can give the player and coach’s extremely valuable performance data. Notational analysis has played a vital role in squash with one of the most influential systems developed by (Sanderson & Way 1977), later developed further by (Sanderson 1983). Brown & Hughes, (1995) showed that if the data is given correctly as in the correct amount, time and terminology, then it has a positive effect on performance.

Literature review

Perturbations in squash

Hughes et al (1998) suggested that the perturbation theory in all sports is exciting for analysts as smaller match providing data can be focused upon, rather than analysing multiple amounts of data. Enabling the analyst to entirely focus on, one aspect of a player’s performance, which will help identify any key areas for improvement. Previous research illustrates that Hodges et al (1998) focused on players with different skill levels analysing if the same interruptions in the game were able to be highlighted. The experiment focused on noting what particular shot enforced a perturbation from a steady state of play to an unsteady state of play. After much analysis the study found that elite squash players along with recreational squash players could both recognize the perturbation shot on a regular basis. These results of Hodges et al (1998) investigation signify and illustrate that perturbations do occur in squash and that they are not impossible to identify as viewer and code as an analyst. This research gives further support and reliability to this chosen topic area.

Squash is not the only sport where perturbations have been analysed. Previous studies have looked at perturbation occurrence in football. Hughes et al (1998) investigated openings in on goal by marking divisions on the pitch to distinguish where the opportunity on goal was attempted from, an approach which similar to the cell divisions used in squash (Murray and Hughes 2001). The attempts on goal were coded from where the player took the shot from as were the positions and the number of the player. This was done by using different symbols to signify the start of a perturbation. Hughes et al (1998) study found that perturbations were present in football and they could be observed accurately through the use of hand notation systems developed by Sanderson & Way (1977).

Murray et al (2008) analysed perturbations in elite squash to generate performance profiles. The aims and objectives of the study were to identify what causes perturbations in elite squash and to create performance profiles of two elite players. Three male and three female squash players were used and all were international right handed players ranked in the top ten of the world. Only competitive games were used, to indicate an honest evaluation of their game. A hand notation was also used to code and notate the perturbations. The system provided data very similar to that of Davies et al (2008) study. Data which showed , what shot was used for the perturbation, where on the court the shot was played from and total number of shots in the rally if the rally regained stability. Both inter and intra reliability systems were used to draw out accurate findings. Murray and Hughes (2001) template of the court was used to accurately code, where the perturbation was made from. The information drawn out was placed into spreadsheets and compared using a measure of error calculated in the form of a percentage (Hughes et al., 2004). An error difference of 10 % was acceptable for this investigation. The investigation found that the two male players had two very different perturbation profiles in attack and defence compared to the traditional profiles based on winners and errors.

The investigation entailed that a drop, volley drop and boast all are key strokes which cause a perturbation. This finding is similar to the one of Hughes et al (2006) who found that drop, boast and volley drop are also the three main shots which cause a perturbation. The study also drew out that both male and female players use the same strokes to cause a perturbation, therefore it can be said that both male and female squash players have the same style of playing in terms of perturbations. However even thou both male and females use the similar shots to cause a perturbation, the study found that that male players use perturbations more efficiently than women. As over fifty percent of perturbations made by male players, lead to a wining point. Whereas the female players had a percentage lower than thirty with regards to perturbations leading onto critical incidents.

Davies et al (2008) also investigated perturbations, however the study focused on the momentum of perturbations in elite squash. The purpose of Davies et al (2008) work was to gather momentum profiles of male and female elite squash players by using perturbations and comparing momentum profiles from the same matches. Three elite women and three elite men players were used for the study. It was imperative the players were all right handed, all ranked in the top ten in the world and only competitive matches were used, to enable a true indication of the players game, for reliability and validity measures. A total of twenty four matches were analysed, four matches per elite player. The aims and objectives of the study were: To create momentum profiles of elite male and female squash players using perturbations (Davies et al 2008). To identify what effect perturbations have upon the momentum in elite male and female squash players (Davies et al 2008). Consequently to examine whether these data profiles add to the profiles obtained by analysis of playing patterns by the traditional methods (Davies et al 2008).

The data extracted from the study will be similar to this study. The data produced, included, whether a perturbation occurred, who the perturbation was in favour of, where in the rally it occurred, the shot which caused the perturbation, and the cell from which it occurred (Davies et al 2008). Both intra and inter reliability systems were used to ensure perturbations were successfully coded. The study showed and gave a huge insight in to how players attempt to control their attacking and defensive tactics. The work of Davies et al (2008) illustrated that the men’s momentum profiles were very comparable to women’s profiles. The study also concluded that in the majority of the every first game every player tried fewer perturbations than there opposition. This implied the majority of top ten elite players like to create a foot hold in the game before trying to imply any pressure on opponents. However as the match continued and the players established themselves it was evident the majority of them enforced pressure on their opponents through the use perturbations.

Performance profiling

With analysis of perturbations, performance profiles can be created, which will enhance the performances of the players focused on. Hughes et al (2005) also studied perturbations in elite male squash players and created performance profiles for these players. The players were analysed with data being extracted by using a hand notation system. The data extracted from the players was transferred to Microsoft excel to calculate the mean and percentages. The investigation and results proved that Hughes et al (2005) found that perturbations were clear in men’s squash and that the boast, drop and volley drop were the main contributors in causing a perturbation.

Multiple investigations involving performance profiles in squash have been conducted since the first one completed by Sanderson and Way (1979). Hughes (1985) study involved different levels of players by comparing the duration of rallies from elite to recreational squash players. The results showed that elite squash players averaged twice the number of shots per match than county players and three and a half times more than recreational players. The research suggested the reason behind these findings is that elite players had a far better ability of reaching shots due to superior fitness and agility. The experiment identified that the elite, county and recreational players all used the same strokes to move their opposition to the front half of the court. Hughes (1985) justifiably found that recreational players just hit the ball with no real attention to where the position of the opponent was on the court, where as elite players where tactically aware off their opponents position. Murray and Hughes, (2001) later said that “by creating performance profiles it allowed to extract critical elements of player’s performances and enabled to construct sophisticated and strategic plans to enhance performances”.

Perturbations can be analysed and occur in any sports, Soccer is a sport which has been used to examine perturbations. Hughes and Franks (2004) study examined and drew out perturbations from football matches and identified a steady state of play as when a team gains possession, gains territory and loses possession. When the steady state of play was disturbed by a good attacking situation or bad defensive situation a perturbation was logged. After a perturbation occurred the system could react in two different ways, either a shot on goal which is known as critical incident (goal) or the team stabilise the state of play. A critical incident in squash refers to a winner or error. Hughes et al (1998) study found that one in four perturbations can lead onto a critical incident. Hughes and Franks (2004) concluded that by coding and analysing perturbations, coaches were able to develop defensive and attacking tactics and gain an upper hand on the opposition’s style of play. Improving defensive and attacking strategies also helped build accurate performance profile on individual players.

Hughes and Reed (2005) study looked into performance profiling by using perturbations in football matches. After the investigation Hughes and Reed (2005) concluded that a minimum of eight matches are needed to create reliable and useful data collection. As Hughes et al (2001) said that it is imperative to make sure a normative profile has been reached, otherwise statements about performance can be inaccurate. England Squash association use a minimum of four matches per individual players to create a performance profile. Therefore this study will use five matches per player to produce even further useful and reliable data, in order to create accurate performance profiles.

Previous research done by Murray and Hughes (2001) investigated and created tactical performance profiles for elite Level Senior Squash players. This research was done as Murray and Hughes (2001) believed it’s not only important to have analysis on your own performances but it’s also imperative to have an understanding of your opposition’s tactical strengths and weaknesses. By analysing opponent’s strengths and weakness, relevant game plans and tactical plans can be put in place in order to establish a positive outcome in performance. The aim of the paper was to outline the development, methodology and application of tactical performance profiles used with elite level male and female English squash players (Murray and Hughes 2001). Murray and Hughes (2001) focused their analysis on five matches for each profile, and players were selected from the top opposition (non English) male players and the top opposition female players in the world (Murray and Hughes 2001). Only matches of a competitive nature were selected for a true reflection of performances and for reliability and validity purposes. The data was analysed by two computerised notational systems (Brown and Hughes, 1995), one real time and the other lapsed time (Murray and Hughes 2001). Data was extracted from digital recording, this enabled the analysts to rewind and pause the critical incidents in the games and, made certain no data was miss coded. The paper found and concluded that the players could easily outline their own major strengths and weaknesses and of the oppositions. Murray and Hughes (2001) stated that the process alone made the players more analytical and focused in their approach to matches and tournaments, which, arguably, is a positive effect in itself. Therefore this study suggests that performance profiling in squash can have a major influences on not only the player’s performance but also their mental approach to games.

Hand notation analysis

A vast amount of research has been done in the past committed to set up the need for forms of analysis and their significance on the coaching process (Hughes 1996). There are undoubtedly recognized problems in front of any analysts attempting to analyse the events taking place in complex team games, such as football, rugby and hockey. One of the main solutions to this problem has been the use of notational analysis systems (Hughes 1996).

The first ever sport hand notation system in the United Kingdom was created by Downey (1973). Downey (1973) produced a system which enabled the notation of tennis matches. The system allowed the analyst to code what shots were used, positions on the court but also this system catered for the coding of the type of spin used on each shot. This notation system provided a helpful base for the improvement of other racket sports like squash, badminton and racquetball.

Squash has gained the attention of a number of sports analysts because of its simplicity as a game (Hughes 1996). There have been numerous amounts of notation systems that have been created for squash, the most famous one by Sanderson and Way (1977). Sanderson and Way (1977) notation system provides simple individual symbols to notate seventeen different shots, as well as court divisions to code where the shots were played from on the court for precise positional data. However it was found that it can take an estimated five to eight hours of practice before an analyst can become familiar and skilful to record a full match whilst play is in progress (Hughes 1996). Furthermore, processing the information extracted from the system could take as long as an extra forty hours of work (Hughes 1996). Sanderson and Way (1977) notation system was created and used to collect data and illustrate that all squash players play in similar patterns of play when either winning or losing. Even thou this notation system is currently the most efficient and well known in the squash field, it still has its flaws. Firstly it takes a long time to get familiar with the system and secondly, the amount of new information gathered from the system requires a lot of time to process.

A perturbation has to be successfully coded and notated in order to create accurate performance profiles for elite athletes. Hughes and Robertson (1998), created a hand notation systems for players in the Men’s welsh squash squad to analyse each other. This provided visual feedback and diverted player’s attention to the importance of tactical awareness (Murray and Hughes 2001). Hughes and Robertson (1998) produced different types of hand notation systems to cater for all types of players from novice to elite. The simplest system involved notating winners and errors to more complex system involving positions on the court and where that shot was played from. The data produced from this simple and effective notation system was be put into many visual formats which made it easier for the welsh players to see areas for improvement. So it is evident from the review of literature that by analysing and coding perturbation attempts through hand notation systems used by Hughes et al (2005) it is possible to pull out strengths and weaknesses performance profiles can be produced.

Hand notation has not only been used and developed for racket sports alone. Hand notation in soccer has proven to have a major success. Reilly and Thomas (1976) analysed soccer using hand notation systems, where they coded the extent of discrete activities during match play (Hughes 1996). Reilly and Thomas (1976) study not only used a hand notation system, but combined it with an audio tape recorder to investigate in detail the positions and movements of English First Division soccer players. By combining both audio tape recordings and the hand notation system, Reilly and Thomas (1976) were able to draw out and identify the work rates of the players in different positions on the pitch, distances covered during the match and the percentage time of each position in each of every different ambulatory classifications (Hughes 1996). The system enabled to draw out even further details, such as how long the players keep the ball during a match and also, what players carry the ball for longer periods in the match than other players. Hughes (1996) stated that it is clear that hand notation systems offer a detailed record of behaviour during match play, therefore it is possible to draw theories of play from such precise analysis.