The validity of small-sided games in predicting 11-vs-11 soccer game performance

Predicting performance in soccer games has been a major focus within talent identification and development. Past research has mainly used performance levels, such as elite vs. non-elite players, as the performance to predict (i.e. the criterion). Moreover, these studies have mainly focused on isolated performance attributes as predictors of soccer performance levels. However, there has been an increasing interest in finer grained criterion measures of soccer performance, as well as representative assessments at the level of performance predictors. In this study, we first determined the degree to which 7-vs-7 small-sided games can be considered as representative of 11-vs-11 games. Second, we assessed the validity of individual players' small-sided game performance in predicting their 11-vs-11 game performance on a continuous scale. Moreover, we explored the predictive validity for 11-vs-11 game performance of several physiological and motor tests in isolation. Sixty-three elite youth players of a professional soccer academy participated in 11 to 17 small-sided games and six 11-vs-11 soccer games. In-game performance indicators were assessed through notational analysis and combined into an overall offensive and defensive performance measure, based on their relationship with game success. Physiological and motor abilities were assessed using a sprint, endurance, and agility test. Results showed that the small-sided games were faster paced, but representative of 11-vs-11 games, with the exception of aerial duels. Furthermore, individual small-sided game performance yielded moderate predictive validities with 11-vs-11 game performance. In contrast, the physiological and motor tests yielded small to trivial relations with game performance. Altogether, this study provides novel insights into the application of representative soccer assessments and the use of continuous criterion measures of soccer performance

Examining the reliability and predictive validity of performance assessments by soccer coaches and scouts:The influence of structured collection and mechanical combination of information

Soccer coaches and scouts typically assess in-game soccer performance to predict players’ future performance. However, there is hardly any research on the reliability and predictive validity of coaches’ and scouts’ performance assessments, or on strategies they can use to optimize their predictions. In the current study, we examined whether robust principles from psychological research on selection – namely structured information collection and mechanical combination of predictor information through a decision-rule – improve soccer coaches’ and scouts’ performance assessments. A total of n = 96 soccer coaches and scouts participated in an elaborate within-subjects experiment. Participants watched soccer players’ performance on video, rated their performance in both a structured and unstructured manner, and combined their ratings in a holistic and mechanical way. We examined the inter-rater reliability of the ratings and assessed the predictive validity by relating the ratings to players’ future market values. Contrary to our expectations, we did not find that ratings based on structured assessment paired with mechanical combination of the ratings showed higher inter-rater reliability and predictive validity. In contrast, unstructured-holistic ratings yielded the highest reliability and predictive validity, although differences were marginal. Overall, reliability was poor and predictive validities small-to-moderate, regardless of the approach used to rate players’ performance. The findings provide insights into the difficulty of predicting future performance in soccer

Methodological Issues in Soccer Talent Identification Research

Talent identification research in soccer comprises the prediction of elite soccer performance. While many studies in this field have aimed to empirically relate performance characteristics to subsequent soccer success, a critical evaluation of the methodology of these studies has mostly been absent in the literature. In this position paper, we discuss advantages and limitations of the design, validity, and utility of current soccer talent identification research. Specifically, we draw on principles from selection psychology that can contribute to best practices in the context of making selection decisions across domains. Based on an extensive search of the soccer literature, we identify four methodological issues from this framework that are relevant for talent identification research, i.e. (1) the operationalization of criterion variables (the performance to be predicted) as performance levels; (2) the focus on isolated performance indicators as predictors of soccer performance; (3) the effects of range restriction on the predictive validity of predictors used in talent identification; and (4) the effect of the base rate on the utility of talent identification procedures. Based on these four issues, we highlight opportunities and challenges for future soccer talent identification studies that may contribute to developing evidence-based selection procedures. We suggest for future research to consider the use of individual soccer criterion measures, to adopt representative, high-fidelity predictors of soccer performance, and to take restriction of range and the base rate into account