## 3 Results  
### Descriptive Analysis  
Table 3 provides a descriptive summary of the analyzed points (\(n\) = 971). As shown, the majority of players initiate the point with a first serve (61.6%), directing it fairly evenly across the three service quadrants, with percentages ranging from 29.9% to 33.7%. The predominant type of rally is the short one, present in 51.5% of the points recorded, followed by the medium rally, which represents 31.5%. As for the final hitting zone, it has been observed that most of the shots are made from behind the baseline, in the hitting zone 4 (49.9%), followed by the hitting zone 3 (24.3%). These finishing shots are similarly distributed between forehands and backhands, accounting for approximately 37% each. Most of the winners had their first bounce in zone 1 (18.4%), while unforced errors were evenly distributed between shots that hit the net and throw off the baseline, both around 20%. Finally, there is a slight advantage for the player who makes the serve, who wins 56% of the points. However, this difference over the remaining player is small, with the opponent's unforced errors being the main reason for scoring points (30.1% of total points, and 53.8% when considering only the points earned by the serving player). In all the variables analysed, except for the service box criterion, significant differences were found when applying the \(\chi 2\) goodness of fit test. \begin{table}
\begin{tabular}{l l l l l l l l l} \hline \hline
**Criterion** & **Code** & **n** & **\%** & **\(\chi 2\) Goodness-of-Fit** & **Criterion** & **Code** & **n** & **\%** & **\(\chi 2\) Goodness-of-Fit** \\ \hline SERVICE & AD & 459 & 47.3 & \(\chi 2\) = 2.893 & & ACE & 50 & 5.1 & \(\chi 2\) = 280.300 \\ BOX & DE & 512 & 52.7 & \(p\) = 0.089 & FINAL & BH & 366 & 37.7 & \(p\) \(<\) 0.000 \\ \hline SERVICE & DF & 45 & 4.6 & \(\chi 2\) = 472.501 & & STROKE & FH & 359 & 37.0 & \\  & FS & 598 & 61.6 & \(p\) \(<\) 0.000 & & OTH & 196 & 20.2 & \\  & SS & 328 & 33.8 & & & & & & \\ \hline TARGET & B & 309 & 31.8 & \(\chi 2\) = 217.610 & & & & & \\ SERVICE & NA & 45 & 4.6 & \(p\) \(<\) 0.000 & & & & & \\  & T & 290 & 29.9 & & FINISH & FZ1 & 179 & 18.4 & \\ BOX & W & 327 & 33.7 & & ZONE & FZ2 & 59 & 6.1 & \\ \hline RALLY & LN & 165 & 17.0 & \(\chi 2\) = 174.812 & & & & & \\  & MD & 306 & 31.5 & \(p\) \(<\) 0.000 & & & & & \\  & SH & 500 & 51.5 & & & & & & \\ \hline  & HZ1 & 90 & 9.3 & \(\chi 2\) = 640.601 & & & & & \\  & HZ2 & 56 & 5.8 & \(p\) \(<\) 0.000 & & WINNER & RW & 427 & 44.0 & \(\chi 2\) = 14.098 \\ HITTING & HZ3 & 236 & 24.3 & & & & & & \\  & HZ4 & 485 & 49.9 & & & & & & \\  & SZ & 104 & 10.7 & & & & & & \\  & & & & & & & & \\  & & & & & & & & \\ \hline \hline \end{tabular} _Note: AD: advantage; DE: device; DF: double fault; FS: first serve; SS: second serve; B: serve to body zone; NA: not available; T: serve to T: zone; W: serve to wide zone; LN: long rally; MD: medium rally; SH: short rally; HZ1= HZ4: hitting zones 1 to 4; SZ: service zone (ace or double fault); ACE: ace (direct point from serve); BH: backhand; FH: forehand; OTH: other stroke; BSO: baseline out; SLO: sideline out; NT: ball into the net; FZ1=FZ5: finish zones 1 to 5; RW: receiver wins; SW: server wins; RWFE: receiver wins with forced error; RWUE: receiver wins with unforced error; RWUE: receiver wins with winner; SWUE: server wins with unforced error; SWUE: server wins with unforced error; SWUE: server wins with winner._  
\end{table} 
Table 3: Descriptive analysis of the study. Table 4 presents an analysis of the first serve, differentiating the points initiated from the deuce side and the advantage side. The results indicate significant differences in the \(\chi^{2}\) goodness-of-fit test for both sides and all the variables analysed. In addition, a comparison was made to evaluate whether there are significant differences between the different variables considered in the research and the side from which the service is initiated.