<p>The association of high schools with certain colleges definitely exists, but I doubt the performance of prior grads is the major factor here. Many schools publish matriculation lists and colleges probably have an access to such information from any school. If a school sends its grads to top-colleges every year, this should tell other colleges that the grads are doing well in competitive environment. So it is hard to see any logic in this. For example, applicants from my school have NEVER gone to Swarthmore, while regularly accepted to Yale, Williams, Amherst, Brown, Dartmouth.</p>