First-Serve Advantage and Emerging Tactical Limitations in Elite U-14 Boys’ Tennis: A Les Petits as Case Study

Abstract

This study investigates the tactical patterns and effectiveness of serve strategies in elite U-14 international boys’ tennis. Using an observational methodology, we analyzed 971 points from the quarterfinals to the final of the Les Petits As 2023 tournament, a prestigious event for junior players. Data were collected using the OBSTENNIS-JUNIOR-S23 instrument with the LINCE PLUS recording tool and processed with SPSS 25 and THEME 6 Edu software. The findings reveal that the first serve is significantly more effective than the second serve, particularly in short rallies (0–4 shots), where serves directed to the T-zone achieved the highest success rates. U-14 players did not exhibit a dominant serving pattern compared to professional players, distributing their serves relatively evenly across different target areas. Additionally, most players remained in deep baseline positions rather than stepping forward, limiting their ability to capitalize on serve placement. Tactical inefficiencies were evident in the execution of the serve +1 shot, where errors often extended rallies unnecessarily. These findings highlight the need for targeted training interventions to improve serve placement, forward positioning, and decision-making. Implementing these improvements could facilitate a smoother transition to higher levels of play and optimize performance in junior tennis competitions.

1. Introduction

In tennis, competition plays a crucial role in determining the technical, tactical, and psychological development of young athletes. This is particularly evident in categories such as U-12 and U-14, where players transition from learning foundational skills to refining competitive strategies. The developmental significance of competitions such as “Les Petits As”, widely regarded as the “World Championship for U-14 players”, has been a proving ground for numerous future stars of professional tennis, including Rafael Nadal, Roger Federer, Kim Clijsters or Martina Hingis, who showcased their talents at this prestigious event early in their careers. This tournament has been highlighted as a platform for players to compete at an international level, preparing them for professional careers in the sport [1,2]. Despite this, the tactical and technical dynamics of junior players, particularly in early categories, remain underexplored, limiting the understanding needed to optimize training methodologies.

Research consistently emphasizes the importance of initial strokes—including the serve and the serve +1 sequence—in determining match outcomes, as they often influence the tactical direction of the point. At junior levels, these strokes are particularly critical because they allow players to take advantage of their strengths early in the point while minimizing prolonged exchanges that could expose technical or physical weaknesses, especially at junior levels [2,3,4]. Previous studies reveal that most points in junior tennis are resolved within the first five shots, underscoring the critical need to enhance tactical efficiency during these sequences [3,5]. Moreover, the differences in tactical behaviour between professional and junior players highlight a significant gap in the tactical knowledge and execution required for higher levels of competition. These differences, as observed by García-González et al. [6], emphasizes the need for individualised training programmes that promote the development of situational awareness and decision-making skills.

From a developmental perspective, junior competitions act as important benchmarks of players’ current abilities and potential indicators of future professional success, albeit with certain limitations [1,7]. Additionally, psychological factors such as motivation, concentration, and emotional control play a crucial role in determining performance outcomes in young players.

The significance of tactical training during the early stages of a player’s career cannot be overstated. Torres-Luque et al. [4] emphasize that tactical competencies, such as positioning and shot selection, are critical for developing effective play styles in adolescence. Furthermore, the integration of notational analysis in evaluating these competencies provides objective and actionable insights. Klaus et al. [3] demonstrated that U-14 players often struggle with maintaining consistency in serve and serve +1 sequences, leading to higher error rates and missed opportunities for point construction.

Current research offers limited insight into the specific tactical strategies of U-14 athletes during competition, often focusing instead on older or professional players [8]. This knowledge gap poses a challenge for designing effective, age-specific training programs that integrate tactical, technical, and psychological development. This study aims to fill this critical void by employing advanced notational analysis to examine tactical patterns, particularly during serve and serve +1 sequences, in U-14 players. By identifying key behaviours like shot placement and positioning, we seek to provide coaches with actionable data to optimize player development. The ultimate goal is to foster foundational tactical competencies during these formative years, thereby improving current performance consistency and facilitating a more seamless transition to advanced levels of competition

2. Methods

2.1. Design

This observational study aimed to identify game patterns in U-14 tennis using the observational methodology [9]. The design employed [10] was defined as nomothetic, as it included all points played from the quarterfinals to the finals in the boys’ category; the follow-up, as it focused on a single tournament (Les Petits As, held in 2023); and unidimensional, as concurrent behaviours were not considered. This design guided methodological decisions regarding sample selection, observation and recording instruments, and the analysis procedure.

2.2. Sample

The sample consisted of points played in the boys’ singles matches at the Les Petits As 2023 tournament. We analyzed 971 points from 7 matches (quarterfinals to final), involving 8 unique male players (U-14 category). All points from these matches were included to ensure a complete observational dataset of elite junior tennis performance under competitive conditions. Early tournament rounds were deliberately excluded to focus on the high-pressure knockout stages, where tactical patterns are most evident in elite junior tennis. The study was approved by the Ethics Committee of the Faculty of Education and Sport Sciences at the University of Vigo (application 05-090425), ensuring compliance with ethical and methodological standards.

2.3. Instruments

The observation instrument used in this study is the OBSTENNIS-JUNIOR-S23, a category system designed to capture the various technical and tactical patterns observable in U-14 tennis during the 2023 season (see

Table 1. OBSTENNIS-JUNIOR-S23 observation instrument.

CRITERIA	CODE	DESCRIPTION
SERVICE BOX	DE	The player serves from the deuce side
	AD	The player serves from the advantage side.
SERVICE	FS	The point is played with the first serve
	SS	The point is played with the second serve.
	DF	The server commits a double fault.
TARGET SERVICE BOX	T	Serve directed to the T zone.
	B	Serve directed to the middle of the service box (body zone).
	W	Serve directed to the wide third of the service box.
RALLY LENGTH	SH	Short rally (0–4 shots), including the serve.
	MD	Medium rally (5–8 shots), including the serve.
	LN	Long rally (9+ shots), including the serve.
HITTING ZONE	HZ1	One foot inside the service box.
	HZ2	One foot between the first half of the service line and the baseline.
	HZ3	One foot between the second half of the service line and the baseline.
	HZ4	Both feet outside the baseline.
	SZ	Ace or double fault (serve zone)
FINAL STROKE	FH	Forehand shot.
	BH	Backhand shot.
	OTH	Other types of shots (drop shot, smash, volley, etc.).
	ACE	Ace (direct serve).
FINISH ZONE	FZ1-FZ5	Zone of the court where the ball is directed (only for winners).
	NET	The final shot goes into the net.
	SLO	The final shot goes out through the sideline.
	BSO	The final shot goes out through the baseline.
WINNER	SW	Server wins the point.
	RW	Receiver wins the point.
POINT ENDING	SWW	The server wins with a winning shot.
	SWUE	The server wins due to an unforced error by the opponent.
	SWFE	The server wins due to a forced error by the opponent.
	RWW	The receiver wins with a winning shot.
	RWUE	The receiver wins due to an unforced error by the opponent.
	RWFE	The receiver wins due to a forced error by the opponent.

and Figure 1). This instrument is an adaptation of several previous observational systems that aimed to achieve similar objectives [11,12]. The OBSTENNIS-JUNIOR-S23 consists of nine criteria that form a category system, ensuring both exhaustiveness—meaning that all possible values or behaviours for each criterion are represented—and mutual exclusivity, which implies that each observed behaviour can only be coded into one category per criterion, avoiding any overlap between categories. Data collection was carried out using LINCE PLUS software, version 2.1.0.

2.4. Procedure

Data collection was carried out by obtaining and editing the boys’ singles quarterfinal, semifinal, and final matches from the 2023 Les Petits As tournament. The footage was sourced from the official Les Petits As YouTube channel (https://www.youtube.com/@lespetitsas, access on 1 October 2024). A fixed camera was positioned at the background of one of the sides of the court at an appropriate height to ensure clear and accurate visualization of the match. There were no issues with observability during the analysis.

Before conducting the data quality tests, which were performed by two experts in tennis and observational methodology, specific training on the use of the observation instrument was provided. This training involved familiarizing the observers with the observation instrument and the LINCE PLUS recording software [13], version 2.1.0, a validated tool for systematic observational studies in sport and behavioural sciences, through nine two-hour sessions over three weeks, using videos of men’s tennis matches from the 2022 season. The two expert observers are university professors with experience in teaching research master’s programs, where they deliver a module on observational methodology in sports science. Both have numerous scientific publications on racket and paddle sports.

To ensure rigour in the recording process [14], the quality of the recorded data was monitored by calculating intra- and inter-observer agreement using the Kappa coefficient [15], calculated using the LINCE PLUS software. Both concordances were performed on a set of 100 points that were not part of the final sample (approximately 1/10 of the final sample). The intra-observer Kappa value was 0.95 for the first observer and 0.94 for the second, while the inter-observer Kappa was 0.93 (see

Table 2. Degree of reliability of the study.

Criteria	Intra-Kappa Obs1–Obs1	Intra-Kappa Obs2–Obs2	Inter-Kappa Obs1–Obs2
Start & end point	1	1	1
Service box	1	1	1
Service	0.99	0.98	0.99
Target Service box	0.92	0.9	0.87
Rally length	0.95	0.94	0.94
Hitting zone	0.92	0.91	0.88
Final Stroke	0.96	0.97	0.95
Finish zone	0.88	0.89	0.88
Winner	0.99	0.98	0.99
Point ending	0.89	0.9	0.87
Average	0.95	0.94	0.93

).

Following these calculations, any discrepancies identified between the two observers were resolved through discussion and joint review. Despite the high agreement indices, this step allowed for refinement and alignment of the coding process. After resolving the discrepancies, only the second observer conducted the final analysis of the 971 points in the study sample.

Once the data collection was completed, an Excel file was created to document the sequence of actions for each analysed point. This Excel file was flexible enough to facilitate the automatic transfer of the data to a file format compatible with IBM-SPSS version 25 and THEME version 6 Edu [16], the software employed for the statistical analyses in the study. THEME is specifically designed to identify recurring behavioural structures that are not apparent through traditional methods [17,18], providing deeper insights into the players’ tactical patterns.

2.5. Data Analysis

All statistical analyses were performed using the IBM-Statistical Package for the Social Sciences, version 25.0 (IBM-SPSS Inc., Chicago, IL, USA). Statistical significance was considered for p-values less than 0.05.

A descriptive analysis of the study variables was carried out both globally and stratified by serve type (first or second serve) and serve side (deuce or advantage).

The χ2 test was used to examine differences between the categories of each criterion employed (χ2 goodness-of-fit test) and to compare differences between the deuce side and the advantage side (χ2 independence test).

Additionally, the effect size was calculated using Cramér’s V to assess the strength of the observed associations, with the following interpretation: 0.00–0.10: very weak, 0.10–0.20: weak, 0.20–0.30: moderate, 0.30–0.40: relatively strong, 0.40–0.50: strong, and 0.50 or more: very strong. An analysis of adjusted residuals was also conducted to identify significant deviations from expected frequencies, providing further insight into the relationships between the variables.

To identify playing patterns, the software THEME 6 Edu (PatternVision Ltd., Reykjavik, Iceland) was used, a specialized statistical analysis tool designed to detect temporal patterns in sequential data. The search criteria applied were: (a) the presence of at least three T-patterns in the observed sequence set; (b) a 90% redundancy reduction adjustment for similar T-pattern occurrences; and (c) a significance level of 0.005.

3. Results

3.1. Descriptive Analysis

Table 3. Descriptive analysis of the study.

Criterion	Code	n	%	χ2 Goodness-of-Fit	Criterion	Code	n	%	χ2 Goodness-of-Fit
SERVICE BOX	AD	459	47.3	χ2 = 2.893	FINAL STROKE	ACE	50	5.1	χ2 = 280.300
	DE	512	52.7	p = 0.089		BH	366	37.7	p < 0.000
SERVICE	DF	45	4.6	χ2 = 472.501		FH	359	37.0
	FS	598	61.6	p < 0.000		OTH	196	20.2
	SS	328	33.8		FINISH ZONE	BSO	208	21.4	χ2 = 269.082
TARGET SERVICE BOX	B	309	31.8	χ2 = 217.610		SLO	140	14.4	p < 0.000
	NA	45	4.6	p < 0.000		NET	196	20.2
	T	290	29.9			FZ1	179	18.4
	W	327	33.7			FZ2	59	6.1
RALLY LENGHT	LN	165	17.0	χ2 = 174.812		FZ3	32	3.3
	MD	306	31.5	p < 0.000		FZ4	65	6.7
	SH	500	51.5			FZ5	92	9.5
HITTING ZONE	HZ1	90	9.3	χ2 = 640.601	WINNER	RW	427	44.0	χ2 = 14.098
	HZ2	56	5.8	p < 0.000		SW	544	56.0	p < 0.000
	HZ3	236	24.3		POINT ENDING	RWFE	60	6.2	χ2 = 334.942
	HZ4	485	49.9			RWUE	276	28.4	p < 0.000
	SZ	104	10.7			RWW	91	9.4
						SWFE	70	7.2
						SWUE	292	30.1
						SWW	182	18.7

Note: AD: advantage; DE: deuce; 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; NET: 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; RWW: receiver wins with winner; SWFE server wins with forced error; SWUE: server wins with unforced error; SWW server wins with winner.

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 χ2 goodness of fit test.

Table 4. Analysis of the first serve.

		First Serve (Deuce)			First Serve (Advantage)			DE-AD Comparison
Criteria	Code	N	%	χ2 Goodness-of-Fit	N	%	χ2 Goodness-of-Fit	χ2 of Independence
TARGET SERVICE BOX	B	71	23.0	χ2 = 14.932 p < 0.001	102	35.3	χ2 = 3.744 p = 0.154	χ2 = 13.111 p < 0.000 V = 0.148
	T	120	38.8		81	28.0
	W	118	38.2		106	36.7
RALLY LENGHT	LN	51	16.5	χ2 = 60.524 p < 0.000	42	14.5	χ2 = 56.478 p < 0.000	χ2 = 1.161 p = 0.559
	MD	96	31.1		101	34.9
	SH	162	52.4		146	50.5
HITTING ZONE	HZ1	27	8.7	χ2 = 222.117 p < 0.000	25	8.7	χ2 = 230.118 p < 0.000	χ2 = 5.919 p = 0.205
	HZ2	15	4.9		17	5.9
	HZ3	70	22.7		77	26.6
	HZ4	160	51.8		151	52.2
	SZ	37	12.0		19	6.6
FINAL STROKE	ACE	31	10.0	χ2 = 77.472 p < 0.000	16	5.5	χ2 = 91.526 p < 0.000	χ2 = 5.337 p = 0.149
	BH	117	37.9		103	35.6
	FH	114	36.9		118	40.8
	OTH	47	15.2		52	18.0
FINISH ZONE	BSO	65	21.0	χ2 = 126.184 p < 0.000	69	23.9	χ2 = 94.917 p < 0.000	χ2 = 8.029 p = 0.330
	SLO	41	13.3		43	14.9
	NET	53	17.2		58	20.1
	FZ1	82	26.5		51	17.6
	FZ2	12	3.9		14	4.8
	FZ3	9	2.9		12	4.2
	FZ4	19	6.1		15	5.2
	FZ5	28	9.1		27	9.3
WINNER	RW	124	40.1	χ2 = 12.042 p < 0.001	110	38.1	χ2 = 16.474 p < 0.000	χ2 = 0.268 p = 0.605
	SW	185	59.9		179	61.9
POINT ENDING	RWFE	22	7.1	χ2 = 88.029 p < 0.000	16	5.5	χ2 = 110.093 p < 0.000	χ2 = 7.877 p = 0.163
	RWUE	71	23.0		73	25.3
	RWW	31	10.0		21	7.3
	SWFE	21	6.8		28	9.7
	SWUE	88	28.5		98	33.9
	SWW	76	24.6		53	18.3

Note: 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; NET: 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; RWW: receiver wins with winner; SWFE server wins with forced error; SWUE: server wins with unforced error; SWW server wins with winner.

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 χ² 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. In this comparison, statistically significant differences were found in the target service box variable when applying the χ² independence test. The size of the effect, assessed using Cramér’s V, indicates that the differences are weak (V = 0.148). When analysing the adjusted residuals, notable differences are observed in the distribution of the target service box variable according to the service side (deuce or advantage). In particular, the adjusted residues show a significant pattern in the body category (intermediate zone of the quadrant), where the advantage side presents a positive value (3.3), indicating a higher frequency observed than expected. Conversely, the deuce side in this same category has a negative value (−3.3), suggesting a lower frequency than expected.

In the “T” category (T zone), the pattern is reversed: the advantage side has a negative value (−2.8), while the deuce side shows a positive value (2.8). This indicates that points starting from the deuce side tend to be directed more frequently to this zone compared to the advantage side. In the ‘W’ category (wide zone), the adjusted residues do not show significant values (residues close to 0), which suggests that there is no relevant difference in the distribution of serves towards this zone between the two sides.

Table 5. Analysis of the second serve.

		Second Serve (Deuce)			Second Serve (Advantage)			DE-AD Comparison
Criteria	Code	N	%	χ2 Goodness-of-Fit	N	%	χ2 Goodness-of-Fit	χ2 of Independence
TARGET SERVICE BOX	CN	66	36.7	χ2 = 15.600 p < 0.000	70	47.3	χ2 = 44.770 p < 0.000	χ2 = 57.309 p < 0.000 V = 0.418
	T	78	43.3		11	7.4
	W	36	20.0		67	45.3
RALLY LENGHT	LN	49	27.2	χ2 = 8.233 p < 0.016	23	15.5	χ2 = 22.797 p < 0.000	χ2 = 6.967 p < 0.031 V = 0.146
	MD	53	29.4		56	37.8
	SH	78	43.3		69	46.6
HITTING ZONE	ZG1	23	12.8	χ2 = 144.167 p < 0.000	15	10.1	χ2 = 145.108 p < 0.000	χ2 = 3.357 p < 0.500
	ZG2	11	6.1		13	8.8
	ZG3	54	10.0		35	23.6
	ZG4	90	50.0		84	56.8
	ZGS	2	1.1		1	0.7
FINAL STROKE	ACE	2	1.1	χ2 = 79.867 p < 0.000	1	0.7	χ2 = 83.838 p < 0.000	χ2 = 1.880 p < 0.598
	BH	75	41.7		71	48.0
	FH	71	39.4		56	37.8
	OTH	32	17.8		20	13.5
FINISH ZONE	BSO	35	19.4	χ2 = 43.111 p < 0.000	39	26.4	χ2 = 59.676 p < 0.000	χ2 = 15.914 p < 0.026 V = 0.026
	LTO	23	12.8		29	19.6
	NET	40	22.2		25	16.9
	Z1	26	14.4		19	12.8
	Z2	10	5.6		3	2.0
	Z3	5	2.8		6	4.1
	Z4	24	13.3		7	4.7
	Z5	17	9.4		20	13.5
WINNER	RW	82	45.6	χ2 = 1.422 p = 0.223	66	44.6	χ2 = 1.730 p = 0.188	χ2 = 0.030 p < 0.862
	SW	98	54.4		82	55.4
POINT ENDING	RWFE	14	7.8	χ2 = 54.200 p < 0.000	8	5.4	χ2 = 63.865 p < 0.000	χ2 = 7.475 p < 0.188
	RWUE	43	23.9		44	29.7
	RWW	25	13.9		14	9.5
	SWFE	8	4.4		13	8.8
	SWUE	56	31.1		50	33.8
	SWW	34	18.9		19	12.8

Note: 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; NET: 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; RWW: receiver wins with winner; SWFE server wins with forced error; SWUE: server wins with unforced error; SWW server wins with winner.

presents the analysis corresponding to the second service, following the same procedure as in the previous case. Statistically significant differences were observed in the χ² goodness of fit test for all the variables analysed and on both sides of the service. Likewise, the χ² independence test identified relevant differences in the target service box, rally length and finish zone criteria. Regarding the magnitude of these differences, evaluated by Cramér’s V, it was determined that for the target service box criterion, the differences were of relatively strong magnitude, while for rally length and finish zone, the differences were very weak.

The adjusted residues provided detailed information on serve patterns. From the advantage side, there was a higher proportion of serves directed to the body and wide zones (adjusted residues of 1.9 and 4.9, respectively), while serves directed to the T zone were significantly less frequent (−7.3). Conversely, from the deuce side, throws to the T-zone were more common (adjusted residual of 7.3), while those directed to the body and wide zones were less frequent (−1.9 and −4.9, respectively). These findings reflect a differentiated pattern in the selection of the service zone depending on the side from which the serve is made. In relation to the length of the rallies, a higher proportion of long rallies (adjusted residual of 2.5) was observed from the deuce side, while medium rallies were less frequent (−1.6). In contrast, from the advantage side, long rallies occurred less frequently (−2.5) and medium rallies showed a slight tendency to be more common (1.6). The short rallies presented a homogeneous distribution between both sides, with adjusted residues close to zero, which indicates a balance in this aspect.

Finally, the areas where the points ended were analysed. From the deuce side, a greater tendency was identified for balls to end up in the Z4 zone (adjusted residue of 2.7), while from the advantage side, this zone was used less frequently (−2.7). In addition, from the side of the advantage, a slight predominance of balls that ended up outside the side and outside the baseline was observed, with adjusted residues of 1.7 and 1.5, respectively. In the NET, Z1, and Z2 categories, the adjusted residuals were close to zero, indicating a more balanced distribution of serves between both sides.

3.2. Serve Patterns of Play

Figure 2 presents a detailed analysis of the success rate of the points, broken down by first and second serve, considering the side from which the point was started (deuce or advantage), as well as the target area of the service (body zone, T-zone, and wide zone). In addition, the distinct types of rallies (short, medium, and long) are included. A general interpretation of the data is provided below.

The first serve shows a higher success rate than the second serve in almost all combinations of zones and rally types. On the first serve, particularly high success rates are observed in short rallies, excelling especially when the serve is directed to the T-zone (73.4% on the deuce side and 81% on the advantage side) or the wide zone, reaching a rate of 71% on the deuce side and 75.4% on the advantage side. In contrast, the second serve features lower success rates across all rally types, with a noticeable decrease in short rallies, except when the serve is directed to the body zone, where the success rate is 61.5% on the deuce side and 65.5% on the advantage side.

When analysing the first serve separately and evaluating the success rate according to the side from which the serve is made (deuce or advantage), it is observed that the differences are minimal. The same is true for the second service.

In short rally points, regardless of whether the point starts with the first or second serve, a slight advantage of approximately 5% in the success rate was observed when the serve is made from the advantage side. However, this success rate is reversed in cases where the service is directed towards the body zone with the first serve.

4. Discussion

This study analysed the tactical patterns of U-14 tennis players, focusing on serve effectiveness, rally length, and point outcomes. The results indicated that the first serve was significantly more effective than the second serve, particularly in short rallies. The success rate of the serve varied depending on the target area, with first serves directed to the T-zone exhibiting a higher winning percentage, particularly in short and medium-length rallies. Additionally, most points were finished within the first four shots, emphasizing the critical importance of initial stroke sequences.

4.1. First Serve Analysis

The analysis of the first serve in U-14 players highlights several key tactical aspects that differentiate them from U-18 and professional players [11]. Regarding service target zones, the data reveal that U-14 players do not show a strong preference for a single service area, as their serves are distributed relatively evenly between the T-zone and wide zone on the deuce side and to the wide zone and body on the advantage side. This contrasts with professional players, who typically show a higher frequency of T-zone serves, as this placement limits the returner’s angle and increases the likelihood of an advantageous court position after the serve [19]. Other research [2] found similar trends in U-12 and U-14 players, where junior athletes displayed a less defined preference in serve placement, highlighting a potential developmental difference in tactical awareness and execution.

The relationship between serve effectiveness and rally length further emphasizes the importance of optimizing the first serve. In our study, short rallies (0–4 strokes) were the most frequent, followed by medium rallies, reinforcing the role of the serve and serve +1 shot in match success. These results align with Fitzpatrick et al. [20], who demonstrated that players dominating short rallies tend to win matches at a significantly higher rate. However, compared to professional players, U-14 athletes exhibit lower efficiency in capitalizing on strong serves, often leading to extended rallies due to less aggressive serve +1 execution and making more errors [2]. The distribution of impact zones further supports this trend, as U-14 players predominantly hit their first shot after the serve from deep baseline positions. This suggests a reluctance to step into the court and take control of the point, differing from professional players who frequently position themselves more aggressively inside the baseline following their serve. This pattern has been previously noted in junior tennis, where players often lack the physical and tactical development to efficiently transition from serve to an offensive position [21].

These tactical differences between U-14 and professional players may also be influenced by physical attributes such as strength and neuromuscular coordination. Younger players often have less developed muscle strength and coordination, which may limit their ability to execute more aggressive shots or step inside the baseline after serving. Additionally, these players are still developing the physical endurance required to maintain a more aggressive playing style, which is typical of older players. The physical limitations could partially explain why U-14 players are more likely to engage in extended rallies rather than capitalizing on their first serve. As noted by Waldziński et al. [22], improvements in motor coordination and tennis skills during early adolescence are crucial for enhancing performance in tennis.

Finally, an analysis of the final stroke and point-ending zones reveals that U-14 players most frequently finish points in central areas, whereas professional players often finish points by moving the opponent and forcing them to more defensive positions [23]. This difference suggests that junior players may lack the tactical awareness or execution ability to consistently use wide angles to finish points effectively. In contrast, professional players strategically use these zones to maximize offensive opportunities and limit the opponent’s recovery time.

4.2. Second Serve Analysis

The tactical analysis of the second serve in U-14 players also reveals several differences compared to U-18 and professional players. In terms of serve placement, the data indicate that these young athletes tend to prioritize body serves, with a particularly high frequency on the advantage side compared to the deuce side. Meanwhile, the use of the T-zone drops significantly on the advantage side, while it remains more prevalent on the deuce side. Unlike professionals, who strategically play their serves to the opponent’s backhand [19], U-14 players show a more conservative approach, aiming to ensure serve consistency rather than creating an immediate offensive advantage. Similar tendencies were observed in the study by Rodríguez-Campos & Martínez-Gallego [2], where U-12 and U-14 players also exhibited a preference for central serves, reflecting a developmental stage where serve variation is still not fully optimized. Examining the connection between the second serve and rally length further highlights its tactical implications. The data confirm that short rallies (0–4 strokes) are the most frequent outcome following a second serve, with medium-length rallies (5–8 strokes) occurring less frequently. This pattern aligns with previous research [20], which emphasizes the decisive role of early exchanges in match outcomes. However, compared to professionals, U-14 players appear less capable of turning the second serve into an immediate tactical advantage, often leading to extended exchanges due to a lack of offensive power in their serve +1 shots. Rodríguez-Campos & Martínez-Gallego [2] also observed that younger players frequently adopt a more neutral or reactive stance following their second serve, rather than imposing their game from the start of the rally. The hitting zones where players contact the ball after their second serve further illustrate this tendency. Most U-14 players play their first shot from deep baseline positions. Prior studies on junior tennis have found that younger players often struggle to transition into offensive positions after serving [21], indicating that further emphasis on movement and positioning would be beneficial in training sessions. Additionally, Vacek et al. [24] found that professional players had a more stable ball impact location on the serve, which may contribute to their ability to control positioning more effectively after the serve. This contrasts with U-14 players, who may not yet have developed the consistency needed to place themselves optimally after serving. Analyzing the areas where points are finished provides additional insight into the tactical execution of U-14 players. The most common finishing zone for points following a second serve is the central zone. This differs from the patterns observed in professional players, who more frequently finish points in wide zones to force their opponents into uncomfortable defensive positions [23].

4.3. Game Patterns

An in-depth analysis of game patterns reveals notable trends in serve effectiveness and rally dynamics among U-14 players. The first serve success rate (60.9%) aligns with findings from Rodríguez-Campos & Martínez-Gallego [2], who reported similar percentages in U-12 and U-14 players. Notably, serves directed to the T-zone had the highest winning percentages (65–67.9%), a pattern consistent with previous research indicating that professional players also favour this zone to gain a tactical advantage [19]. In contrast, the second serve demonstrated a lower success rate (54.9%), with players preferring wide serves over T-zone placements, possibly as a risk-reducing strategy. The relationship between serve placement and rally length further supports the importance of serve precision. Short rallies (0–4 strokes) had the highest winning percentages across all serve placements, reinforcing Fitzpatrick et al.’s [20] findings that dominating early exchanges significantly increases the probability of winning a match. Compared to professional players, U-14 athletes showed a lower tendency to end points quickly with aggressive serve +1 strokes, often leading to extended rallies or neutral ball exchanges [21]. These findings suggest that U-14 players require further training to enhance their ability to capitalize on advantageous serve placements and effectively transition into offensive positions after the serve.

4.4. Practical Applications

The findings suggest that training programs for U-14 players should emphasize improving first serve accuracy and serve +1 shot execution. Coaches should incorporate drills that simulate match scenarios where players must transition quickly from serve to baseline play. Given that short rallies dominate match play at this level, enhancing players’ ability to capitalize on these early exchanges could yield substantial performance improvements. Additionally, the tactical differences observed between U-14 and professional players indicate that developmental training must be carefully structured to bridge these gaps. Serving strategies should evolve from a generalized approach to a more targeted execution, progressively resembling professional-level patterns.

4.5. Limitations of the Research and Future Perspectives

While this study provides valuable insights, it is limited by its focus on a single tournament. Future research should analyse multiple tournaments across different surfaces to determine if tactical patterns remain consistent. Moreover, expanding the sample to include both male and female players would offer a more comprehensive perspective on tactical development in junior tennis. Besides this, future studies should explore how psychological and physical attributes influence tactical decision-making. Additionally, the integration of tracking technologies, such as Hawk-Eye, could provide deeper insights into shot placement and movement patterns, further refining training methodologies for young players.

5. Conclusions

This study provides valuable insights into the tactical patterns of U-14 tennis players, particularly regarding serve strategies. The findings indicate that while junior players demonstrate a functional approach to both first and second serves, their tactical execution remains less developed compared to higher-level players. Serve placement lacks variation, with a strong preference for central serves, particularly on the second serve, which limits their ability to control rallies from the outset. Additionally, U-14 players tend to remain in deep baseline positions rather than transitioning forward, reducing their capacity to capitalize on advantageous serve placements. Rally length analysis reinforces the dominance of short points, yet junior players struggle to maximize early exchanges due to inconsistencies in serve +1 execution. Moreover, finishing patterns reveal a preference for central zones, contrasting with professional players who utilize wider angles to create more effective point-ending opportunities. These results suggest that targeted training programs focusing on serve variation, forward positioning, and finishing strategies could enhance the tactical development of U-14 players, ultimately facilitating their progression to more advanced levels of competition.