Theories can be measured according to multiple metrics. The current default appears to be predictive accuracy, but this lists others, such as scope. If theory A predicts better but narrower and theory B predicts worse (in A's domain) but much more broadly, which is a better theory?

Others might be related to simplicity and whatnot. For example, if a theory is numerical but not explanatory (such as scaling laws or the results of statistical fitting) this theory might be useful but not satisfying.