<p>It is not necessary to apply to 20 schools --it is a strategy that works in place of true knowledge about admissions, but using greater knowledge to apply in a more careful way to fewer schools would bring a better outcome for the student imo. The missing element for those who do scattershot: knowledge of the admissions process. I suppose in its absence, applying to 20 schools vs. 10 would up the odds. But for those educated about the process, it is not necessary at all.</p>