**4. Discussion**

This aim of this study was to evaluate the serve and return statistics in elite padel players regarding courtside and gender. The notational analysis of this research is one of the most important contributions because of the lack of previous research regarding this aspect in padel. The main results showed that the serving pair had a significant advantage in rallies, which lasted until shot 7 in women and shot 12 in men (Figure 2). Considering that serve advantage is lost after the fourth shot in tennis, this finding probably reflects the nature of padel in that it is much harder to play a winning shot, due to the court dimensions and structure, meaning that when a pair is dominating the rally, as at the start of the point when serving, it often takes more shots to finish the rally compared to tennis [16]. Regarding gender, men won a significantly higher percentage of points when serving than women (62.5% vs. 48.5%), as happens in other sports like tennis, where men obtain 14% more points with their serve than their female counterparts [34,35]. These gender differences may be due to the fact that male players are taller and can jump higher, which would enable them to sustain for a longer period of time an offensive position at the net [36,37]. However, deeper analysis and complementary variable collection is encouraged for a more relevant advance in this knowledge. In tennis, previous studies reported that men's serves had an impact on rally outcome in rallies that lasted four shots [22]. This impact of the serve was corroborated by other research, which found that the serving pair won the most rallies containing 1 to 4 shots [38]. These different results in padel sugges<sup>t</sup> that the influence of service extends some way into the rally in padel because the predominance of the "serve and volley" strategy allows the serving pair to move close to the net first and adopt an offensive position [9,39]. Despite serve advantage being lost when the return players use technical actions that facilitate a change of position, such as lobs, this transition from offensive to defensive position only appears in 37% of points [40]. On the other hand, the results showed first serve effectiveness as being close to 90%. Even though there were no gender significant differences, the higher occurrence of first service faults reported by women could be due to a higher predisposition to obtain a direct point by forcing the first service [15].

With regards to serve direction, the results of this study showed how players served primarily towards the side wall, increasing that percentage on the left side (advantage), which is usually the place where more decisive points are fought. The greater distance covered by the player serving during the point [39] could explain this crossed direction of the serve towards the glass, since it would allow him to buy more time to occupy a better position at the net. Furthermore, the bounce on the side wall may complicate the return stroke, which could cause a greater number of errors, as other authors have claimed [15]. Other studies reported that the high percentage of serves to the side wall on the left side could be explained by the hand-dominance of the players [12]. Thus, since most padel players playing on the left side of the court are right-handed, servers would seek to serve towards the side wall to seek both the backhand of the return as well as the uncertainty of the wall bounce. No differences between genders were found in serve direction. Similar studies in other racket sports, such as tennis, showed that the serve aimed at the "T" was the most effective in winning the point [41]. However, on the left side of the court, better results are obtained when players serve cross-court or open [42]. It is important to highlight that some of these results regarding serve direction could be related more to players' hand dominance than court side [12], so further research is warranted.

The results of this study confirmed that the beginning of each point in professional padel seems very important and decisive for increasing the chances of winning the point. Then, serve effectiveness is directly related to the opponent's serve-return skills [17]. The results showed that a very high percentages of serve returns stayed in (around 90%), but no differences regarding gender or courtside were found. This effectiveness percentage is higher than in other racket sports such as tennis, where serve power is higher [43]. Furthermore, return height and direction in padel may allow couples in the defensive position to execute a stroke that allows them to send the attacking couple to the back of the court [11]. Previous authors showed how sending deep lobs to the corners and close to the walls will keep the rivals far from the net. However, the results of our study showed that players hit about 60% straight and 40% lob shots. These data are confirmed by a previous analysis in a national padel

competition, and reflect the importance for the player serving to run toward the net and be able to approach the net to make the straight return more advantageous [16]. Furthermore, the return's height and direction showed significant di fferences with regards to players' gender and the side of the court. Thus, women executed more lobs and cross-court returns than men. This higher use of lobs by female players has been confirmed in previous studies that sugges<sup>t</sup> a more defensive playing style among women [10,44,45]. Thus, because over-head strokes (smash and tray) are the most successful shots during a match, with a significantly higher percentage in the male category [10,46], players returning the serve have to use the lob only in comfortable positions to overcome their opponents at the net, since a poorly executed lobbed return could have as a response a winning smash from the serving players. At the national level, the lob return of serve achieved long rallies 48.8% of the time for good depth (around 5.5 m beyond the net) o ff first serves and 61.8% of the time o ff second serves, and 79.8% of the time for excellent depth (around 8.5 m beyond the net) irrespective of serve [16].

With regards to playing side, players returning the serve on the left side stroke more with their backhand than forehand, and play more straight and down the line strokes than players on the right side, corroborating the findings of Torres-Luque et al. [10], who found that about 75% of serves were directed to the backhand of players. This fact could be due to a higher game aggression of players when resting in the left side, not allowing serving players to take the lead in the point [9,47]. Furthermore, these di fferences in return with regards to playing side are especially important considering that 75% of the decisive points are played on the left side of the court [35].

Although this is the first study addressing serve and return statistics in professional padel, the study presents some limitations. First, contextual variables such as match status were not registered. Given the influence of situational variables on game performance [48], it would be very interesting to include such information in future research on padel. On the other hand, other variables that may affect serve and return statistics, such as serve speed or spin and players' hand dominance [12,22,43], have not been taken into account. Finally, the sample was limited, so future studies should analyze a greater number and tournaments and padel players.
