The term self-organized criticality is used for dynamical systems that appear to spontaneously reach a critical state. Ordinarily, in well-known models like percolation or the Ising model, criticality is reached by tuning the model parameter to the critical value. A possible explanation for self-organized criticality in the sandpile model, is that the dynamics of the model serve as a mechanism to inconspicuously tune a parameter to the critical value. In this talk, various mathematical subtleties of such an explanation are discussed.