# Determinants of Y-Shaped Agility Test in Basketball Players
## 1 Introduction  
Agility is defined as \"a rapid whole-body movement with change of velocity or direction in response to a stimulus\" and is considered to be important for many sports [1]. Some authors also use this term when the rapid movement of the body does not involve a reaction to a stimulus and the task is pre-planned [2; 3]. Nowadays, it usually denotes a change of direction speed (CODS), which is an independent ability with only a small aspect of agility performance [4]. The common variance among the change of direction speed test and agility test was only 10%, suggesting that they are measuring distinct qualities [1]. The term \"reactive agility\" was created to make a clear distinction between the pre-planned change of direction speed and agility, including the perceptual and decision- making element [1; 5; 6]. In the first model indicating factors determining reactive agility, the change of direction speed was one of the two main components. The second component consists of the perceptual and decision-making factors [7]. Later, this model was modified and agility in invasion sports was determined by the cognitive, physical, and technical aspects [4]. The cognitive component included decision-making and accuracy (visual scanning, anticipation, pattern recognition), and the physical component replaced the change of direction speed; however, its subfactors remained almost unchanged (straight sprinting speed, leg muscle qualities as strength, power, and reactive strength). The primary model was supplementedby the technical component, which was the subcomponent of change of direction speed in the previous model [4]. However, no study to date has investigated the contribution of the technical component to reactive agility because of the difficulty of doing so. Most studies have assessed only the motor component (physical factors) and fewer have assessed the sensory component (perceptual and decision-making factors) of reactive agility [1; 6; 7; 8; 9; 10]. Invasion sports involve several changes of direction and most of them include responses to stimuli, either movement of an opponent, teammate, or ball [4]. These types of sports include basketball, in which reactive agility is one of the most important factors of performance [9; 11]. To test reactive agility, the task must include some external stimuli to stress athletes' visual scanning and decision-making capacities [12]. It has also been shown that ability to react to an external stimulus is an effective method of differentiating the skill levels of athletes [4]. The most common model used is a Y-shaped agility test, in which athletes receive a stimulus that requires them to complete a 45\({}^{\circ}\) cut to the left or right [12]. It is usually used for basketball players as well [11; 13]. This test is characterized by a non-stop running scenario and relatively small directional change (45\({}^{\circ}\)) with a total running distance of 10 m (5 m forward + 5 m forward after directional change). Therefore, it is considered a velocity-oriented test [14]. The sensory or perceptual and decision-making aspect was expressed by the reaction to only one visual stimulus with two possible responses (left or right). There are several more reactive agility tests which differ in structure, e.g., shorter running distance or higher number of stimuli [15; 16; 17]. It was found that the number of possible responses affects the reaction time [18]. Compared to these types of tests, the Y-shaped agility test represents the motor rather than the sensory component. Although all reactive agility tests consist of sensory and motor components, less is known about their contribution to reactive agility in basketball players. Whereas several studies have investigated the relationship between the reactive agility performance and parameters of motor abilities [11; 15; 16] from the practical and theoretical point of view, it could be of interest to know about the contribution of both components to reactive agility.