## 3 Performance Analysis in Sports  
Performance analysis in sports refers to the systematic process of recording, analyzing, and interpreting performance data with the overarching aim of enhancing athletes' or teams' performance (Figure 1) [41; 42; 43]. This entails the careful observation and quantification of key performance indicators (KPIs), which vary across different sports modalities, such as individual pursuit (e.g., track cycling or swimming), collective sports (e.g., soccer or basketball), and endurance activities (e.g., marathon running or triathlon). These KPIs encompass a wide range of elements such as skills, techniques, tactics, and physiological parameters, which are meticulously scrutinized during both training sessions and competitive events [4]. Although the primary goal of performance analysis is to improve performance, it also plays a crucial role in injury prevention and future performance prediction, thereby assisting in talent discovery [44; 45]. To achieve these goals, performance analysis employs a variety of methodologies, including observational analysis, video analysis, notational analysis, time-motion analysis, and data analysis from wearable devices [46; 47; 48; 49; 50; 51; 52; 53; 54; 55; 56; 57; 58]. Each of these techniques holds its unique role in contributing valuable insights into sports performance and can be defined as:  
* **Observational Analysis:** This refers to the methodical process of gathering, documenting, and assessing data by directly observing athletes or sporting events. It involves trained observers who meticulously record various facets of athletic performance. This analytical approach serves as a foundation for comprehensive assessments of athletes' strengths, weaknesses, and areas for improvement. It can be performed using just the naked eye and recorded or supplemented with external data from different sources [4; 59]. * **Video Analysis:** A technique that utilizes recorded game or training footage to study and review an athlete's performance or a team's tactical approach. It allows for the analysis of various aspects such as skills, techniques, player movement, and team formations. The use of various video speeds, from slow motion to frame-by-frame, enables intricate scrutiny of every action, providing detailed feedback to athletes and coaches [11; 47; 51; 52; 53; 55; 60; 61]. * **Notational Analysis:** This systematic process involves the recording and analysis of discrete events that occur during a match or training session. Each event is notated or coded to provide a quantitative means of recording the performance. The data gathered provide an objective record of performance and can offer insights into the effectiveness of tactics, strategies, and individual player actions [10; 56; 62; 63]. * **Time-Motion Analysis:** This is a method used to quantify the physical demands of a sport, by recording and categorizing all movements of an athlete during a match or training session. It provides insight into the duration and intensity of various activities, the frequency of specific movements, and the rest periods. The information gathered can guide training and recovery programs and help evaluate players' physical performance during the competition [57; 58; 60; 61; 62; 64; 65; 66]. * **Data Analysis from Wearable Devices:** Wearable technology has gained significant traction in sports, with devices like Global Positioning System (GPS) trackers, heart rate monitors, and accelerometers now commonly used. These devices capture a range of physiological and biomechanical data, including heart rate, speed, distance covered, body temperature, and sleep quality. Analysts use this data to monitor player health, access games and training sessions' external loads, and optimize performance [47; 48; 49; 51; 57; 67; 68; 69]. This rigorous combination of processes of performance analysis is usually conducted by sports or performance analysts, also known as sports statisticians [70; 71].