In my undergraduate years, one of my professors always talked about this one mathematician who was talking about "good" graphs and wondered about the existence of such a graph. Apparently this mathematician could not find such a graph, and then proceeded to show that the probability that such a graph existed was 1 by using a probability measure.
Does anyone know to whom my professor was referring? [I apologize if such a question is inappropriate for this site.]
Not sure without more context, but my best guess is the mathematician was Paul Erdős and technique you are talking about is the Probabilistic Method.