  An n-vertex graph is called C-Ramsey if it has no clique or independent set
of size C log n. All known constructions of Ramsey graphs involve randomness in
an essential way, and there is an ongoing line of research towards showing that
in fact all Ramsey graphs must obey certain "richness" properties
characteristic of random graphs. More than 25 years ago, Erd\H{o}s, Faudree and
S\'{o}s conjectured that in any C-Ramsey graph there are
$\Omega\left(n^{5/2}\right)$ induced subgraphs, no pair of which have the same
numbers of vertices and edges. Improving on earlier results of Alon, Balogh,
Kostochka and Samotij, in this paper we prove this conjecture.
