Notational analysis in soccer: past, present and future.

Notational analysis is now widely used in soccer, the result of influential previous research, its use by well respected individuals within the sport and the development of affordable technology. Currently most, if not all, professional soccer teams all over the world use some form of video feedback coupled with some statistical summary of events. The details of which are difficult to determine comprehensively due to the secrecy surrounding performance analysis and the need to gain an advantage over the opposition. This paper therefore predominantly discusses some of the influential published papers and comments on the conclusions derived from them. Current issues that are relevant to both researchers and coaches of soccer, such as sample size, operational definitions, performance over time, invariant behaviour and perturbations, are described and discussed using practical examples where possible. Possible future directions in notational analysis research are briefly considered including fuzzy logic and artificial neural networks.