  In our recent work \cite{StojnicCSetam09,StojnicUpper10} we considered
solving under-determined systems of linear equations with sparse solutions. In
a large dimensional and statistical context we proved results related to
performance of a polynomial $\ell_1$-optimization technique when used for
solving such systems. As one of the tools we used a probabilistic result of
Gordon \cite{Gordon88}. In this paper we revisit this classic result in its
core form and show how it can be reused to in a sense prove its own optimality.
