On the other hand, some epistemologists, including Robert Nozick, have denied closure principles on the basis of reliabilist accounts of knowledge. Nozick, in Philosophical Explanations, advocated that, when considering the Gettier problem, the least counter-intuitive assumption we give up should be epistemic closure. Nozick suggested a "truth tracking" theory of knowledge, in which the x was said to know P if x's belief in P tracked the truth of P through the relevant modal scenarios.
I chanced upon this article not too long ago, and I was wondering what was meant here. What is meant by reliabilist accounts of knowledge? And how does it work against such basic idea that if we know q and q entails x, then we know x, which should be basic common sense derived from logic?