Fit statistics for individual and accretive models of self-citation based on 41.6 million references from 1.6 million articles with 2 or more authors published during 2002-2005.

The best-performing model at each step is the one with the largest log-likelihood (LL); only the highest-ranking of which are shown in steps 2 and following. Models comprise the predictors from the best-performing models in all previous steps along with the newly added category indicated by the plus sign (+). AUC (Area Under the receiver operating characteristic Curve), given as a percentage, roughly measures the accuracy of estimated probabilities. The number of terms in the model is denoted by nf, excluding intercept.