Evaluating the Effectiveness of Penalty Kicks in the UEFA Champions League: Optimal Techniques and Directions for Scoring Success

This study examined the strategic execution of penalty kicks in professional soccer, focusing on the high-stakes environment of the UEFA Champions League. Utilizing a dataset of 243 penalty kicks from five seasons (2018/2019–2022/2023), sourced from YouTube and cross-referenced with Transfermarkt, we employed a detailed nine-zone goal classification system to analyze shot distribution and success rates. We investigated various factors influencing penalty outcomes, including match stage, home-field advantage, minute of the match, current score, player status, previous score, footedness, and rebound goals. Findings indicated that shots aimed at the center and upper areas of the goal have the highest success rates. It was also found that home advantage considerably enhances scoring chances in both group and knockout stages. This research fills a gap in the literature by providing insights into penalty kick strategies in the UEFA Champions League, offering valuable implications for coaching practices, player training, and analytical frameworks in high-pressure scenarios.


Introduction
In professional soccer, penalty kicks represent pivotal moments capable of altering the course of a game, influencing tournament outcomes, and impacting the broader strategic framework of teams and leagues.These moments are not merely about scoring; they encapsulate a complex interaction between psychological tension, tactical decision-making, and significant economic implications (Crnjac et al., 2016) (Fariña et al., 2013).Penalty kicks offer a relatively straightforward goal-scoring opportunity, yet they occur in high-pressure situations (Ellis & Ward, 2022).Statistically, penalty kicks are crucial, comprising approximately 7% of all goals (Gelade, 2014).The tactical advantage of a successful penalty is clear, as demonstrated by historical data indicating that teams that convert penalties win more frequently (Dalton et al., 2015).For instance, during the World Cups and European Championships from 2000 to 2010, teams awarded a penalty kick during a match had a 52%-win rate.This figure increased to 61% upon a successful conversion and decreased to 29% when missed (Dalton et al., 2015).These data underscore the substantial impact of penalty kicks on game outcomes.
The impact of penalty kicks extends beyond the immediate game, influencing league standings and even promotional prospects for clubs.Successful penalties can significantly impact a team's seasonal trajectory in league settings.For example, teams that effectively execute their penalty opportunities are 37% more likely to achieve promotion (Jamil et al., 2021).Because the organizational framework and implementation of tournaments such as the World Cup and European Championship resemble those of the UEFA Champions League, data from these first two tournaments can be relevant and applied to research focusing on the Champions League.Additionally, focusing exclusively on the UEFA Champions League allows us to analyze penalty kicks in one of the most high-profile and competitive club tournaments in the world.This focus provides a unique opportunity to examine how these factors influence performance under the intense pressure and high stakes of the Champions League.
Moreover, the sport's current money-driven environment magnifies the importance of penalty kicks.A scored penalty at a vital moment can generate new financial opportunities for a club.A team advancing past the group stage and becoming one of the last 16 in the Champions League can bring in about 10 million euros, while simply qualifying grosses over 15 million euros (Banerjee, 2023).Conversely, a missed penalty and the resulting lost tournament and prize money can halt a club's investments, which prevents future competitiveness in the worst-case scenario.Success in the Champions League can also strengthen a club's chances of sustainable prosperity by maintaining better performance in national leagues through the financial boost from European competitions (Ruta et al., 2022).
Such financial considerations contribute to the situational pressure that may cause issues during a game, especially at penalty kicks.Regardless of a player's skill level, the chances of missing the goal altogether increase by 6% in a pressure-filled moment (Brinkschulte et al., 2023).The execution of penalty kicks involves considerations, from the psychological pressure experienced by the player to the choice of shot direction.The additional pressure of playing in a tournament, where every game could potentially be the last, may increase this challenge.This psychological tension is particularly pronounced in the Champions League, whose global audience and substantial financial rewards entail exceedingly high stakes.
Given these dynamics, this paper aims to address a critical gap in the existing literature by focusing on the unique pressures and dynamics of penalty kicks in the UEFA Champions League.We sought to identify the most effective strategies for executing penalty kicks within this high-pressure context, focusing on the optimal techniques and directions that augment scoring probabilities.We also aimed to optimize coaching practices, player training, and analytical frameworks used by teams by addressing the following research question (RQ): RQ: What is the most efficient strategy and direction for scoring penalty kicks from the spot?

Literature Review
Previous research has highlighted various factors that influence the outcome of a penalty kick and methods of predicting the ball's direction from a goalkeeper's perspective.High-tension moments can greatly affect cognitive capabilities (Sandi, 2013).The presence of a large audience can increase the pressure on the penalty taker.Simple elements, such as moving advertisements behind the goal, can negatively impact the accuracy of shooters who use a goalkeeper-dependent kicking strategy (Paterson et al., 2020).The home-field advantage is another crucial factor to consider.During the COVID-19 outbreak, soccer matches were played without fans, which altered penalty kick success rates.Studies have found that away teams are more likely to miss penalties in a full stadium due to the hostile environment, while home teams are more likely to score (Ferraresi & Gucciardi, 2021).Without fans, the success rate of away teams' penalty kicks in Europe's top five soccer leagues increased, whereas the success rate of home teams dropped.This analysis also considered the location of each game to determine whether the home-field advantage translates to the Champions League.
While this paper focuses on the shooter rather than the goalkeeper, both players experience pressure that can interfere with their decision-making at critical moments (Brimmell et al., 2019) (Kimmel & Rogler, 2018) (Masters et al., 2007).Goalkeeper-focused research can be reevaluated, adapted, and applied to the shooter and vice versa.For example, Dicks et al. (2010) investigated the psychological aspects of penalty kick before a shot is taken, examining how obvious deceptions by shooters, such as gazing in a nontargeted direction and employing unusual foot positioning, can improve scoring chances (Dicks et al., 2010).A challenge for goalkeepers is their frequent inability to process visual information appropriately and promptly, highlighting the importance of knowing facts about the shooter in advance (Jamil et al., 2020) (Kurz et al., 2020) (Nayan & Islam, 2022).Buscà et al. (2022) found that shot direction could be predicted immediately before the ball is kicked by observing three variables: the kicker's dominant foot, arm abduction on the nondominant side, and the foot orientation of the nondominant foot (Buscà et al., 2022).
Another important variable is the timing of the penalty kicks.The 536 penalties recorded in the Champions and Europa Leagues between 2010 and 2015 revealed a high probability of penalties being saved between the 31st and 61st minutes of a match (Almeida et al., 2016).Analysis of all World Cups and European Championships shows a rising number of penalties as the game progresses, the second half reporting double the number of the first half.A greater difference appears when comparing the first and last quarters, with four times as many penalties awarded in the final quarter (Dalton et al., 2015).This also appeared between 2010 and 2020 in the Turkish Super League, in which 27.5% of the 845 penalties were awarded after the 76th minute.Additionally, the lowest miss rate occurred from the 76th minute to the end of the game (Şaban Tuğlu, 2022).Similarly, to Almeida et al. (2016), Tuğlu et al. (2022) recorded the highest miss rate from the 46th to the 60th minute at 23.3%, indicating that the minute of the match significantly affected the success of penalty kicks (Şaban Tuğlu, 2022).
Extensive research on penalty kick shot direction has primarily classified shots into the natural side, nonnatural side, and center (Baumann et al., 2010) (Coloma, 2007).For a right-footed shooter, the natural side is the left, while the nonnatural side is the right; this is reversed for left-footed players.Studies have confirmed that players prefer aiming for their natural side more often than their nonnatural side (Baumann et al., 2010).Additionally, when analyzing the vertical direction of penalty kicks, research has noted that most athletes aim for the lower area of the goal (Bar-Eli & Azar, 2009) (Horn et al., 2021).According to Bar-Eli and Azar (2009), 56.6% of all penalty kicks in top soccer leagues target the lower third of the goal.Their analysis, based on 286 observations, also examined goalkeepers' stopping probabilities concerning the vertical direction of the shot.Despite receiving the most shots, the lower third did not yield the highest success rate, as it also had increased stopping probabilities.Specifically, goalkeepers saved 19.8% of penalty kicks aimed at the lower third (Bar-Eli & Azar, 2009).Some researchers have suggested that properly practicing to aim for the upper area would produce a greater chance to score because the declining miss rate would compensate for the higher saving probabilities when aiming low (Bar-Eli & Azar, 2009) (Horn et al., 2021).Others have argued that the risk of having a low-aimed penalty kick saved outweighs that of missing the goal completely with a high-aimed kick (Almeida & Volossovitch, 2022).This mixed evidence raises the question of whether aiming for the upper or lower area is more effective, considering the higher risk of missing the goal when aiming high (Almeida & Volossovitch, 2022) (Horn et al., 2021), leaving room for further investigation into this issue.
Although previous literature has provided valuable insights into the effectiveness of penalty kicks in various settings, further research is necessary for several reasons.First, most studies on penalty kicks have focused on league settings.Researchers have often combined data from multiple tournaments to enlarge the sample size, but this approach prompts questions about the comparability of different tournaments.The applicability of combined data results is dubious because the context of a penalty kick in an African Cup of Nations qualifier differs significantly from one in a Champions League semifinals.Therefore, this research specifically aims to produce results relevant to the UEFA Champions League, offering a more accurate understanding of penalty kick strategies in this particular high-stakes tournament setting.
Additionally, previous research has overlooked several factors that can increase pressure on the penalty taker.To address this, we included variables such as team captaincy, previous scoring history, current score, and the stage of the match (i.e., group or knockout).Furthermore, the potential for rebound goals is a significant determinant of successful in-match penalties.Unlike shootouts, in-match penalties allow for rebound goals, influencing the kicking strategy.A goalkeeper's save of the initial shot does not guarantee possession.If the ball rebounds into play, the game continues, and the team that reacts faster gains an advantage, often creating another scoring opportunity.Therefore, this study aimed to fill this gap in the literature.

Data
The dataset for this study comprises 243 penalty kicks collected from five UEFA Champions League seasons, specifically from 2018/2019 to 2022/2023.Each penalty kick's replay was sourced from YouTube (https://youtube.com),ensuring that every visual detail of the penalty execution was captured.We then cross-referenced these visual data with additional textual and statistical information from Transfermarkt (https://transfermarkt.com), a comprehensive soccer database that provides detailed match statistics, player profiles, and match events.This dual-source approach-using both visual and textual data-ensured the reliability and accuracy of the variables associated with each penalty kick, thus providing a robust dataset for subsequent analysis.
To achieve a comprehensive understanding of penalty kick distribution and success rates, we categorized the outcomes of observed penalty kicks beyond the conventional three directions commonly used in literature (i.e., natural side, nonnatural side, and center).Instead, a more detailed nine-zone classification system was employed, dividing the goal into nine equal sections both horizontally and vertically.From the kicker's perspective, left (L), center (C), and right (R) represent the left, middle, and right thirds of the goal, respectively.Equally, high (H), middle (M), and low (L) correspond to the upper, central, and lower thirds of the goal.This method allowed for a more detailed analysis of shot selection and success rates.This nine-zone system provides a detailed map of penalty kick placements, enabling a granular analysis of the most likely areas for players to aim and the associated success rates for each zone.

Variables
Match stage is classified as either a group-stage or knockout game.Given the elevated stress levels associated with knockout games compared to group-stage matches, this distinction helps analyze the impact of situational pressure.
Home-field advantage indicates whether the penalty was taken by the home team or the away team.This variable addresses the influence of a supportive or hostile crowd on the kicker's performance.
Minute of the match records the exact minute at which the penalty was awarded.This variable helps to determine whether the timing within the match affects the success rate.
Current score refers to the score at the time of the penalty kick, categorized as winning, drawing, or losing.This variable indicates the pressure level associated with the team's position.
Player status signals whether the penalty taker was the team captain, which may influence their confidence and performance.
Previous score identifies whether the player had already scored in the match, potentially affecting their psychological state and shot choice.
Footedness denotes the preferred foot of the penalty taker (i.e., right, left, or ambidextrous).This helps to analyze any correlation between footedness and shot success or direction.
Foot used records the actual foot used to take the penalty.This variable was included to validate the preferences of ambidextrous players.
Rebound goals indicates whether the penalty resulted in a rebound goal if the initial shot was unsuccessful.This variable assesses the strategic advantage of aiming low for potential rebounds.
Season identifies the specific Champions League season in which the penalty was taken, providing a temporal context for the analysis and helping track any changes over time.

Analysis
We used Microsoft Excel for the entire data process, encompassing data collection, analysis, and visualization.Both numeric and nonnumeric variables were included to comprehensively capture the factors influencing penalty kick outcomes.This approach ensured a robust analysis that considered multiple dimensions of penalty kick dynamics.The primary analytical approach consisted of descriptive statistics to measure frequencies and tendencies, providing a foundational understanding of the dataset.
The use of a nine-zone goal classification enabled a detailed analysis of shot direction and success rates, offering a comprehensive view of penalty kick strategies.This classification divided the goal into nine sections: left high, left middle, left low, middle high, middle middle, middle low, right high, right middle, and right low.By analyzing the data within these zones, we analyzed specific areas of the goal that yielded higher success rates, thus providing insights for optimizing penalty kick strategies.
Overall, this analytical approach, combining descriptive statistics and visual representations, enabled a thorough examination of penalty kick strategies and their effectiveness in the high-stakes environment of the UEFA Champions League.This comprehensive methodology ensured that the findings were both statistically robust and practically relevant for enhancing performance in professional soccer.Table 1 shows the variables and explanations.

Result
The sample size of this research measures 243 penalty kicks from the Champions League seasons from 2018/2019 to 2022/2023 and only includes penalty kicks from the group stage while excluding those from qualifier matches.These penalties were evaluated based on the used foot, shot distribution, and success rate in various scenarios, such as taken at home or away and at the group or knockout stage.The result showed that penalty kicks aimed at the lower corners, particularly the left, were most successful, and home advantage significantly amplified scoring chances.
Overall, 196 of the 243 (80.7%) penalty kicks taken resulted directly in a goal.The two most targeted areas (left low and right low) comprised 54.3% of all the kicks, while the least targeted area (left high) comprised 4.9%.The success rate of each area of the goal was highest when aiming for the middle (92.9%), followed by aiming for the left high (91.7%)and left low (90%) zones.It was the lowest when players targeted the left middle area (58.3%), followed by the middle high, which had a success rate of 60%. Figure 1 shows the shot distribution of all the kicks in absolute numbers, while Figure 2 shows the number of penalty goals in absolute numbers.However, not every missed penalty kick in the figures shown above is due to the goalkeeper saving it, as they also include attempts that missed the goal altogether.The results also align with previous research on natural and nonnatural side preferences.Penalty kicks taken with the right foot went to the left in exactly 50% of all cases, and penalties taken with the left foot went to the right in 53.7% of all cases.The numbers targeting the nonnatural side are similar: 33.5% of penalties taken with the right foot went to the right, and 26.9% of penalties taken with the left foot went to the left.Besides the UEFA Champions League displaying some of the highest quality soccer around the globe, the percentage of athletes aiming for their natural or nonnatural side hardly differs from all previous findings in other settings.Figure 3 presents the shot distribution in absolute numbers by foot used.Next, the following tables provide information on how pressure-related variables influence an athlete's shot selection and how successful penalty kick takers were in each scenario.We implemented tables related to each scenario to form conclusions that will aid the overall effectiveness of future penalty kicks in certain situations.Each of these tables follows the same structure, representing a goal divided into the nine aforementioned areas, as viewed from the shooter's perspective.Every area displays two numbers: the success rate in percent of shots targeting that area and the associated absolute number of kicks.
Table 2 displays the success rate and the number of kicks in the group stage for home and away games.The highest success rates at home are for kicks aimed at the low left (90.9%) zone, followed by high left (87.5%) and low right (86.7%) areas, while the highest success rates away are for kicks aimed at high left (100%), middle middle (100%), and low left (91.7%) zones.The lowest success rate at home is for kicks targeting the high middle (40%) and middle left (50%) areas, while the lowest success rate away is for kicks aimed at the middle right and high middle (66.7% each).Home players most frequently aimed for the low left (33 kicks) and low right (30 kicks), indicating a preference for these areas due to higher success rates.Away players most frequently aimed for the low left (24 kicks) and middle left (10 kicks), reflecting a similar inclination toward areas with higher success rates.The result showed that for both home and away games, aiming for the lower corners of the goal (especially low left) tends to yield higher success rates.There is a notable difference in success rates for middle and high areas, with home games showing more variability in success.The high success rate for kicks aimed at the high left area during away games, although based on a smaller sample size, indicates potential strategic value.Overall, these findings can inform training and strategic decisions for penalty kicks in different match contexts.Table 3 displays the success rate and the number of kicks in the knockout game for home and away games.The success rate for all high and middle areas at home is 100%, indicating strong performance in these zones, while high success rates for away games are seen in the high left (100%), middle middle (100%), and low middle (100%) zones.The lowest success rate at home is for the low left (80%) and low right (85.7%) areas, while the lowest success rate away is for the high middle (66.7%) and middle left and right (both 50%) zones.Nevertheless, home players most frequently targeted the low left (5 kicks) and low right (7 kicks), indicating a preference for these areas despite slightly lower success rates.Away players predominantly aimed for the low left (7 kicks), indicating a strong preference for this area due to relatively higher success rates.The result showed that during knockout games, both home and away players, especially the former, are highly successful when aiming for high and middle areas.However, the preference for lower corners remains strong, particularly the low left.For away games, aiming for the middle of the goal also appears to be highly effective.These findings can be used to inform training and strategic decisions for penalty kicks in high-stakes knockout scenarios.We also compared pressure effects in knockout versus group stages for both home games and away games.In home games, the pressure of knockout stages appeared to boost performance, especially in the middle and high zones.The success rates in knockout stages were significantly higher across these zones compared to group stages (e.g., only 40% success in high middle during group stages versus 100% in knockout stages).This disparity suggests that players under knockout pressure tend to perform better in more challenging zones, possibly due to heightened focus or motivation.
However, in away games, the pressure of knockout stages affects players' choices and success rates more negatively.While the high left and middle middle zones maintained 100% success rates, other zones showed a decreased performance, especially the high right, which dropped to 0%.The middle and low zones also exhibited varied success rates, suggesting that the hostile environment and increased pressure of away knockout games might hamper players' accuracy and decision-making, leading to more cautious or less optimal shot placements.
Overall, the data from Tables 2 and 3 indicate that knockout stage pressure impacts home and away games differently.At home, players seem to thrive under pressure, achieving higher success rates across all zones.On the other hand, in away games, the increased pressure of knockout stages tends to reduce success rates in several zones, particularly in high-risk shots such as those targeting the high right area.This finding highlights the importance of the home-field advantage and the psychological effects of playing under high-stakes conditions.
Table 4 displays the success rate in percent and the absolute number of kicks when aiming for each area of the goal at three different score lines: winning, losing, and drawing.When teams were winning, success rates varied significantly, with the highest success on the right side (100%) and the lowest in the middle (40%) for high shots.For middle shots, success rates were very high, particularly in the middle (100%) and right (100%) zones.Regarding low shots, success rates were consistently high, with the middle area achieving 85.7%, the left 84%, and the right 77.8%.When teams were losing, the success rate is highest on the left (100%) and middle (75%) but lower on the right (62.5%) for high shots.Success rate was high in the middle (100%) but lower on the left (62.5%) and right (57.1%) for middle shots.For low shots, the highest success was on the left (91.3%) and right (87.5%), but success was significantly lower in the middle (50%).When teams were drawing, success rates were high across all directions, with the left and right at 100% and the middle at 50%.Success rates varied, with the highest being in the middle (80%), left at 50%, and right at 66.7% for middle shots.For low shots, success rates were very high, particularly in the middle (100%) and left (95.5%), with the right being slightly lower at 78.6%.Overall, the results showed that penalty kicks aimed at the middle has the highest success rates for winning or losing teams.However, when teams were drawing, low shots in the middle were the most successful.Additionally, aiming for the high right corner was consistently effective when winning or drawing.The lowest success rate for winning teams was for middle-high shots.

Discussion
This research aligns with and extends the findings of Ferraresi and Gucciardi (2021), confirming that a supportive home crowd positively influences penalty kick success, while conversion rates drop-in away games (Ferraresi & Gucciardi, 2021).Specifically, out of 137 penalty kicks taken at home, 82.5% resulted in immediate goals.Conversely, for the 104 penalty kicks taken by away teams, the percentage of immediate goals decreased to 77.9%.These findings affirm that the home-field advantage extends to international competitions such as the UEFA Champions League, corroborating data from national competitions across Spain, Italy, Germany, France, and the United Kingdom.
When analyzing penalty kick distribution, we confirmed that the upper corners of the goal have the lowest stopping probabilities, aligning with Almeida et al. (2016) (Almeida et al., 2016), Bar-Eli and Azar (2009) (Bar-Eli &Azar, 2009), andHorn et al. (2021) (Horn et al., 2021).However, this study found the highest success rate for shots aimed directly at the middle (92.9%), followed by the left high area (91.7%).These variations in findings can be attributed to differences in data collection methodologies.This study included all penalty outcomes, whether saved, missed, or hitting the post, whereas other researchers have excluded certain misses.This methodological difference leads to distinct interpretations of stopping probabilities versus success rates, highlighting the importance of consistent data collection practices.
Comparing this research to Almeida et al. (2016) and Fariña et al. (2013) reveals differences due to varying goal area classifications.Almeida et al. (2016) and Fariña et al. (2013) excluded the top and bottom corners and instead differentiated between center-left and center-right (Almeida et al., 2016) (Fariña et al., 2013).Their highest stopping probability was at the center-left area (19.4%), which aligns with this study's finding of the lowest success rate when aiming for the left middle area (58.3%).Bar-Eli and Azar (2009), using the same goal classification as this research, concluded that the highest stopping probability was at the bottom left corner (24%) (Bar-Eli & Azar, 2009).These discrepancies highlight the challenge of making direct comparisons due to different research focuses and methodologies.
Analyzing pressure-related results, Brinkschulte et al. (2023) indicated the significant impact of pressure, with success rates dropping from 75.1% before the quarter-final to 71.5% from this round onward (Brinkschulte et al., 2023).This study found a different trend, with success rates increasing in knockout games (85.4%) compared to group stages (79.5%).A surprising finding emerged when comparing success rates between knockout stages and group stages.Despite the increased risk of missing the goal altogether in knockout games, the success rate was higher for shots aimed at the highest third of the goal.This trend suggests that players might perform better under higher pressure, although a larger sample size is needed to confirm this finding.
Another unanticipated finding of the research arose when comparing the success rates of penalty kicks in knockout stages versus group stages.Regardless of the game's location, aiming for the highest third of the goal (i.e., left high, middle high, and right high) generally increases the risk of missing the goal entirely.However, in the high-pressure context of knockout stages, where each game could potentially be the last, the success rate for shots aimed at the upper third was higher compared to group stage matches.This result suggests that players perform better under extreme pressure, although a larger sample size is necessary to confirm this trend and provide more robust conclusions.
Overall, this research highlights the complex interplay of psychological and situational factors influencing penalty kick success.By confirming and expanding upon previous findings, this study contributes valuable insights into the strategic execution of penalty kicks in high-stakes environments such as the UEFA Champions League.

Theoretical and Practical Implication
This study offers valuable theoretical insights into the psychological and strategic dynamics of penalty kicks in the UEFA Champions League.The findings contribute to the broader sports psychology literature by highlighting how extreme stress affects cognitive functions.This understanding is essential for developing theoretical models that explain performance variances in athletes, particularly in scenarios demanding precision under pressure.By linking specific performance outcomes to psychological states, our study can help refine existing theories about stress, anxiety, and performance, offering a more detailed understanding of how pressure affects decision-making and execution in sports Moreover, the current study could enhance the theoretical framework of sports performance analytics by providing a granular analysis of penalty kick outcomes based on various factors such as footedness, game stage, and situational pressure.The nine-zone goal classification system particularly offers a more detailed method for analyzing and predicting shot placement and success rates.This approach can be adopted in performance analytics to create more sophisticated models that capture the complexity of player performance and strategy.This methodology and these findings can serve as a basis for further theoretical exploration into how specific variables influence performance metrics in sports.
This study also offers practical applications for improving training, decision-making, and performance analytics in professional soccer.This study's findings can be directly applied to enrich training programs for soccer players.Coaches can use the detailed analysis of shot distribution and success rates to develop targeted training drills that simulate high-pressure scenarios.For example, knowing that aiming for the lower left corner tends to yield higher success rates can help in designing specific drills that focus on improving accuracy in that zone.Additionally, training sessions can incorporate psychological stressors, such as simulated crowd noise or timed drills, to better prepare players for the mental challenges of taking penalty kicks in competitive matches.This practical application can encourage better performance in actual game situations.Furthermore, our insights into the success rates of penalty kicks based on different conditions (e.g., home versus away games, group versus knockout stage) can inform coaches' strategic decisions during matches.Coaches can use these data to decide which players are best suited to take penalty kicks under specific conditions, thereby maximizing scoring chances.For instance, if a player is more successful when aiming for the lower left corner during away games, coaches might prioritize that player for penalty kicks in similar contexts.This strategic approach can hone a team's competitive edge and improve overall performance in crucial moments.

Limitation
Although the current study provides interesting results, it is not without limitations.One limitation is the sample size.The study's dataset comprises 243 penalty kicks from five UEFA Champions League seasons.While this sample provides valuable insights, it may not be large enough to draw definitive conclusions about rarer combinations of variables or trends.A larger sample size would increase the reliability and generalizability of the findings, allowing for more robust statistical analysis and greater confidence in the results.Additionally, the dataset spans five seasons, from 2018/2019 to 2022/2023.While this timeframe provides a recent snapshot, it may not capture long-term trends or changes in penalty kick strategies over more extended periods.The study's temporal scope may miss variations due to evolving playing styles, rule changes, or other contextual factors influencing penalty kicks in different eras.
Another limitation is the reliability of the data source.The data collection relied on replays from YouTube (https://youtube.com) and additional information from Transfermarkt (https://transfermarkt.com).This dual-source approach ensures a degree of accuracy, but it also introduces potential biases due to the variability in video quality, completeness of the footage, and subjectivity in interpreting visual data.Furthermore, the reliance on publicly available sources may limit the comprehensiveness and consistency of the dataset.Another limitation is the exclusion of shootout penalties.The study focuses exclusively on in-match penalties, excluding penalty shootouts.These shootouts, which occur in knockout stages and are high-pressure situations, could provide additional insights into player behavior and strategy.Including shootout data would offer a more comprehensive understanding of penalty kick dynamics under different pressure conditions.

Suggestions for Future Research
To extend the current understanding of penalty kick effectiveness, future research should consider expanding the dataset to include more seasons and additional variables.With a larger sample size, researchers can achieve more robust and generalizable findings.This expanded dataset should include variables such as player age, experience, and psychological profiles to examine how these factors influence penalty kick outcomes.Additionally, including data from penalty shootouts, not just in-match penalties, would provide a more comprehensive understanding of player performance under extreme pressure.This approach would help identify trends and strategies that could further optimize training and performance for players and teams.
Future research could also explore the impact of different coaching strategies and training programs on penalty kick performance.This would include investigating how specific training routines, such as those focusing on shooting accuracy, psychological resilience, and decision-making under pressure, influence success rates.Researchers could conduct longitudinal studies to track the progress of players who undergo specialized training programs compared to those who follow standard training regimens.Moreover, the role of technological aids, such as video analysis and biomechanics feedback, in improving penalty kick performance should be examined.Understanding the effectiveness of various coaching approaches and training techniques would provide practical recommendations for coaches and teams seeking to heighten their competitiveness.
While this study focused on psychological pressure, future research might further investigate the psychological and environmental factors that affect penalty kick success.These factors could include the impact of crowd noise, stadium design, and weather conditions.Researchers could use experimental designs, such as simulated penalty kicks in controlled environments, to isolate specific variables and measure their effects.Additionally, studies could incorporate advanced technologies such as virtual reality to simulate high-pressure situations and measure players' physiological and psychological responses.This research would provide valuable insights into how external factors influence performance and could inform targeted interventions to improve player resilience and accuracy.

Conclusion
The purpose of this study was to identify the most effective strategies for executing penalty kicks in the UEFA Champions League by analyzing various psychological, tactical, and contextual factors that influence scoring success.By examining a dataset of 243 penalty kicks from five seasons, this study identified key trends, such as the preference for aiming at lower corners of the goal, the impact of homefield advantage, and the variances in success rates based on match context and player status.We found that penalty kicks aimed at the lower corners, especially the left, have the highest success rates.Home advantage significantly boosts scoring chances, while high-pressure knockout stages do not deter success.Along with these findings, we found that the pressure of knockout stages affects players' choices and success rates differently than that of group stages.
This study fills a critical gap in the literature by providing specific insights applicable to the high-stakes environment of the Champions League, contrasting with broader, less context-specific analyses of penalty kicks.The findings contribute to the theoretical framework by integrating psychological and situational factors into the analysis of penalty kick success, enhancing the predictive models used in sports analytics.Practically, the study provides insights for coaches and players, suggesting tailored training practices that simulate high-pressure scenarios to improve performance.This research not only advances the academic discourse on penalty kicks but also offers practical recommendations that can be immediately implemented in professional soccer.We hope that future research will build on these insights, expanding the dataset and exploring additional variables to develop strategies and improve the overall understanding of penalty kicks in high-stakes soccer contexts.

Table 1 . Variables and Definitions.
Indication of shooter scored in match prior to taking the penalty kick Current score Score at the time the penalty kick is taken; win, draw, lose Season Indication of in which UEFA Champions League season penalty kick was taken