An investigation of the change of tactics at wimbledon using a computerized scorebook for tennis

Resumen investigation of the change of tactics at Wimbledon

Tactics are an important factor in racket sports. The main characteristics of racket sports are continuous play and changing situations. Match analysis contributes to tactical coaching. Hughes (1994) outlined the purpose of notation as ‘tactical evaluation’. Franks et al (1983) also showed that a computerized system can be used for the purpose of gaining immediate feedback and the development of database. A computerized system provides benefits for tactical coaching. A computerized system has developed by some researchers (Kudo 1995, O’Donoghue and Ingram 2001). However, these systems were not in common use. The authors developed a new computerized scorebook for tennis. The characteristics of the scorebook is getting a time factor immediately. The scorebook can analyze not only the frequency of shots and classifications of results but also time duration of playing, time duration of out-of-play and the time duration of each shot. Historical comparison of match analysis is important on tactical coaching. There is some research about match analysis. The tactical difference among court surfaces were reported by O’Donoghue and Ingram (2001) and O’Donoghue and Liddle (1998). These are not historical researches. A historical comparison of physical factor was reported by Kovacs (2004). The purpose of this study was to clarify the historical characteristics of playing time in tennis using a computerized scorebook for tennis.

Introduction

Tactics are an important factor in racket sports. The main characteristics of racket sports are continuous play and changing situations. Match analysis contributes to tactical coaching. Hughes (1994) outlined the purpose of notation as ‘tactical evaluation’. Franks et al (1983) also showed that a computerized system can be used for the purpose of gaining immediate feedback and the development of database. A computerized system provides benefits for tactical coaching. A computerized system has developed by some researchers (Kudo 1995, O’Donoghue and Ingram 2001). However, these systems were not in common use. The authors developed a new computerized scorebook for tennis. The characteristics of the scorebook is getting a time factor immediately. The scorebook can analyze not only the frequency of shots and classifications of results but also time duration of playing, time duration of out-of-play and the time duration of each shot. Historical comparison of match analysis is important on tactical coaching. There is some research about match analysis. The tactical difference among court surfaces were reported by O’Donoghue and Ingram (2001) and O’Donoghue and Liddle (1998). These are not historical researches. A historical comparison of physical factor was reported by Kovacs (2004). The purpose of this study was to clarify the historical characteristics of playing time in tennis using a computerized scorebook for tennis. Methods 1. Data collection was collected from Wimbledon finals held in 1980, 1981, 1993, 1994, 2004 and 2005. Those matches were defined as a group of 80s (1980 and 1981), 90s (1993 and 1994) and 00s (2004 and 2005). The number of points of all matches was 1,593.

Procedures

2.1 Computerized scorebook for tennis The computerized scorebook for tennis was developed by the authors. It records a time factor using the internal computer clock in 1/100 sec intervals. The scorebook records time data when the scorer clicks a shot button at the same time as a player contacts the ball. Time data can clarify the timing of tennis such as time duration per point, time duration of shots and time duration between points. The accuracy of time duration of shots was verified by Takahashi et al (2006). They reported that the data obtained from the scorebook is highly accurate when the scorer is well trained on its operation and can see the match clearly. 2.2 Data analysis The scorebook was used for data collection. The scorer recruited for this study was adequately trained on scorebook operation. The matches were recorded broadcasts. The scorer could see the matches clearly. Timing data was obtained from the scorebook: time duration per point, rally numbers per point, time duration of service, time duration of ground stroke and time between points. Time duration per point was defined as the time between the impact of service and the impact of the last shot. Rally numbers per point was defined as shot numbers from the service to last shot of point. Service aces were defined that rally numbers was 1. The faults of service were defined that rally numbers were zero and it excluded from analysis. Time duration of service was defined as the difference between the clock time of return of service and the time of service. Time duration of ground strokes was defined as the difference between the time of shot by one player and another. This was only calculated when both players played ground strokes. Time between points was defined as the difference between the time of first service and the time of last shot of previous point. The time of changing ends was excluded from analysis. Timing data was compared by groups of the matches. An ANOVA test was used to compare those timing data on groups of the matches, and Tukey’s HSD test was used for multiple comparisons.

Results

1. Time duration per point A comparison of time duration per point among match groups is shown in Fig. 1. Significant differences existed between 00s and other groups. Time duration per point was longest in the 00s.

Fig.1 A comparison of time duration per point among match groups.

2. Rally numbers per point A comparison of rally numbers per point among match groups is shown in Fig. 2. Significant differences existed among all match groups. Rally numbers per point was longest in the 00s and shortest in the 90s.

Fig.2 A comparison of rally numbers per point among match groups.

3. Time duration of service A comparison of time duration of first service among match groups is shown in Fig. 3. Significant differences existed between the 80s and other groups. Time duration of first service was longest in the 80s. A comparison of time duration of second service among match groups is shown in Fig. 4. Significant differences existed among all match groups. Time duration of second service was longest in the 80s and shortest in the 90s.

Fig.3 A comparison of time duration of first service among match groups.

Fig.4 A comparison of time duration of second service among match groups.

4. Time duration of ground stroke A comparison of time duration of ground stroke among match groups is shown in Fig. 5. Significant differences existed between the 00s and other groups. Time duration of ground stroke was shortest in the 00s.

Fig.5 A comparison of time duration of ground stroke among match groups.

5. Time between points A comparison of time between points among match groups is shown in Fig. 6. Significant differences existed between all match groups. Time between points was longest in the 90s and shortest in the 00s.

Fig.6 A comparison of time between points among match groups.

Discussion

1. Time duration and rally numbers per point Time duration and rally numbers per point was longest in the 00s. Rally numbers became longer, time duration per point became longer. Several reports showed time duration per point at Wimbledon. O’Donoghue and Liddle (1998) reported that time duration per point was 3.69±2.54 sec in the 1996 tournament. O’Donoghue and Ingram (2001) reported that time duration per point was 4.3±1.6 sec on 1997 and 1999 tournaments. In this study, it was 2.70±3.22 sec on 90s and 3.99±4.00 sec on 00s. Time duration per point became longer from the middle of the 1990s. 2. Time duration of service and ground stroke Time duration of the first service was shorter in the 90s and the 00s than in the 80s. It is affected by the innovation of rackets and also changing ball regulations. Time duration of second service was shortest in the 90s and longest in the 80s. Players needed a strong service in the 90s because of increased ‘serve-and-volley’ use. Time duration of ground stroke was shortest in the 00s. Rally numbers per point were also highest in the 00s. Players needed effective baseline-play in the 00s. These are affecting both point-winning and time duration. 3. Time between points Time between points was shortest in the 00s. The rule about continuous play had changed several times. It was determined in 1991 that the time between points should not at any time exceed 25 seconds. Furthermore, it was changed 20 seconds on 1994. Results showed that players obeyed the rule about time between points. In the match of 00s, players used the maximum time interval between points. It is considered that players attempt to recover physical strength during interval time. Conclusions the years, time factors changed historically in the Wimbledon finals. From 80s to 00s, time duration per point became longer, time duration of shot became shorter and time between points became shorter. Players have needed increased physical strength in recent years. A computerized scorebook for tennis is useful for analyzing time factor. It can be utilize for tactical coaching.

Bibliografía

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