Mike Wright and Nobuyoshi Hirotsu of Lancaster University, UK, have developed a mathematical way of modelling soccer matches to optimise substitution strategies.

This probabilistic model is aimed at working out the optimum time to make substitutions or change tactics during a match.

Substitutions usually occurs when a team wins or loses possession and scores or concedes a goal. But, according to Wright, many managers introduce substitutes too late to have a positive impact on a match.

"We evaluate the characteristics by means of maximum likelihood estimators for factors such as home advantage, offensive and defensive strength and their interactions, by taking account of not only goals but also possession of the ball", the researchers say.

Source:
Will Knight, NewScientist.com news service

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