## 1 Introduction  
When people focus their attention on something, they often fail to notice unexpected occurrences, even if they happen right in front of them. This phenomenon is known as inattentional blindness [1] and has been shown to be a highly robust finding in psychology [2, 3]. Over the last few years, a number of studies have applied inattentional blindness paradigms in the field of decision making in sports [4]. Some of these studies have found differences in inattentional blindness between expert team sport athletes and novices. For example, one study showed that expert basketball players detect an unexpected object in a basketball task more often than amateur players do [5]. As team sport players are usually exposed to a whole range of different environmental influences and various stimuli that they have to perceive on the playing field, it is hardly surprising that single pieces of information are sometimes overlooked when the attentional focus is on other stimuli in that moment. This can be explained by the fact that humans have a limited information-processing capacity, and consequently, it is important to primarily focus on the most task-relevant or situation-relevant information for the most optimum outcome [6; 7]. In team sports, this mostly refers to the teammates and opponents as well as the ball. However, situations occur in which players, who are unexpectedly unmarked, are not involved in offensive game situations by their teammates [8]. Two previous studies have shown, for example, that participants watching short videos of basketball or handball plays, often fail to notice an open player, even while deciding who should receive the next pass from the player holding the ball [4; 9]. The oversight of open teammates and opponents can depend on many factors, one of which is the players' positioning on the pitch. When we look at the different positions of players on the pitch individually, for example in football, it becomes apparent that teammates and opponents are usually all placed on the pitch in front of a goalkeeper in football. On the other hand, strikers often receive passes from behind the optimum position for scoring, while running up to the opponents' goal and while teammates and opponents may be positioned to their left, right, behind them, and in front of them. Various on-field and analytical studies have dealt with position-specific skills and specializations in team sports. Skill requirements vary from position to position and it is well-known that certain positions require specific traits [10]. In football, for example, center midfielders (attacking and defensive) have to pick up and process information from multiple sources (e.g., players in front, behind, and next to them) [10; 11]. As they spend most of the playing time in the central parts of the field, it is necessary for them to absorb information from all around them (a 360-degree visual input) to be able to make the best decision possible and achieve optimal performance [12]. This distinguishes them from other players on other positions, such as the goalkeeper's position. So far, it has remained uncertain whether different playing positions in sports (e.g., the goalkeeper compared to offensive players in handball or football, or the quarterback compared to the running back or center in American football) correspond to differences in performance in detecting unexpected objects, unmarked players, or suddenly appearing opponents, due to their different range of tasks and perceptions on the pitch. In three various independent experiments, this hitherto overlooked factor of a possible position-specific inattentional blindness was investigated in football players. We assumed that the strikers would detect an unexpected object (an object being not important for the decision-making task in Experiments 1 and 2, but being important for the sport-specific decision making in Experiment 3) more often compared to the other players.