by Albin Tenga
The broader measures of offensive effectiveness are thought to provide an alternative to goal scoring due to naturally low scoring probability. The purpose of this study was to evaluate how well specific offensive playing tactics collectively predict goal scoring vs. scoring opportunity vs. score box possession in Norwegian elite soccer. The sample included data from 163 out of 182 (90%) matches played in the professional male league during the 2004 season was analysed in three ways: team possessions leading to goals (203 cases compared to1688 random controls), team possessions leading to scoring opportunities (80 cases compared to the remaining 1608 random controls), and team possessions leading to score box possessions (167 cases compared to the remaining 1521 random controls). Multidimensional qualitative data using five ordered categorical variables was obtained to characterize each team possession. Multiple logistic regression analyses showed the same offensive tactics were more effective than their opposite offensive tactics for each of the three team possession outcomes except tactics in the variable starting zone for score box possession. All three team possession outcomes were well predicted, but scoring opportunity (ROC curve area=0.79, 95% confidence interval: 0.74 to 0.84, P<0.001) was superior to the other two. Thus, scoring opportunity is a better alternative measure of offensive effectiveness than score box possession (shooting opportunity), but both are qualified as good measures and, compared to goal scoring, they require smaller samples for meaningful analyses.