# Reliability of Perceptual-Cognitive Skills in a Complex, Laboratory-Based Team-Sport Setting
## 4 Discussion
### Limitations and Future Research  
First, breakthrough showed a disproportionally large number of missing video pairs that can be explained by the high frequency of dynamic kinematic information (e.g., through the attackers' deceptive move). Here, defenders were \"dragged\" from the attacker's postural changes, which led to habitually premature movement initializations. Second, the choice of defensive actions was governed by the doubled but randomized video clip presentation within occlusion conditions. As mentioned before, standing throw and pass, and jump throw and breakthrough, demonstrated similar movement patterns and run-up steps, respectively. Subconsciously, participants could have been aware of previously observed kinematic cues of matching video clips. Previously primed tactical decisions from other attacks could have resulted. We counteracted this problem with a large number of video clips (224 videos per subject) and the inclusion of dummy trials in the test paradigm. Third, although degrees of freedom of the defender's movements were exceptionally high compared to previous studies [14, 20, 21, 22, 23], the pre-specified contact plate positions of our test setup constrained defenders' movement paths. Defending a one-on-one situation in team handball implies varying body and arm positions that also lie between or off the prescribed contact plates. Therefore, only full-body changes of defender position could be analyzed. Nevertheless, the execution of an additional offensive block requires an initial position changing movement. Staying passive and blocking could not be distinguished either, but again, the positioning in the defense was the main focus. That is why we still expected valid insights into tactical defense behavior with this setup. In team handball, the so called \"show-up\" is a typical behavior of defenders. \"Show-ups\" provoke movement changes or discontinuations of an attacker through disconcertion. A show-up normally implies a fast and single step forward up to the 8 m mark, and a fast-paced movement backwards. Other defenders prefer slightly offensive positions at the 8 m line, and not the classically instructed 7 m line position required in our study. Additional contact plates at 8 m and between central and lateral contact plates would broaden the space for defensive actions and allow analyses of so-called triangular movements (a show-up with a lateral move backwards to the side of the ball). Fourth, the TO paradigm by nature presents simple time frames with varying postural cues, but our paradigm is unable to provide a clear identification of cues' decisive contributions in action sequences. Additional spatial occlusion and eye movement registration [50] could deliver combined knowledge about what areas or cues in a visual search field are of significant importance for anticipatory processes and provide information about an athlete's information gathering strategy. The test battery forms a basis for new entry points into future anticipation research in real-life environments in team handball, and overall invasive sports. The rarely considered but crucial aspect of contextual information, or situational probabilities [40, 51], offers fruitful research perspectives in the context of this new test setup. Due to the focus on reliability in this paper and the movement basis of the experimental set up, these factors are not applicable for explanatory approaches of present findings in this study so far. Nevertheless, it must be mentioned that with involvements of these factors, our test battery can lay the foundation for more holistic clarifications in cognition in team sports. Due to its now proven reliable properties, the test setup could be used as a motor tool for modified perceptual training [52] in the future. With further developments and adjustments, it could allow athletes to improve visual information gathering by repeating natural skill executions in a discipline-specific way.