This article presents a reexamination of the Sørensen model. This model derives the pattern of individual careers from structural considerations. If longitudinal data on individual careers are available, Sørensen's model provides two methods to infer the underlying structural parameter. This structural parameter gives a useful measure for unequal career chances. An implementation of these methods, using firm data, shows, however, that they lead to contradictory conclusions; this is shown to be the result of some unrealistic assumptions Sørensen uses in his derivation. Some more realistic assumptions are suggested that produce reasonable results. Finally, it is shown that despite these modifications, the main conclusions of the Sørensen model are preserved. This seems to be promising for future work with this model.