The Probabilistic Method is now a standard tool in the combinatorial toolbox but such was not always the case. The development of this methodology was for many years nearly entirely due to one man: Paul Erdős. Here we reexamine some of his critical early papers. We begin, as all with knowledge of the field would expect, with the 1947 paper Erdős P (1947) Some remarks on the theory of graphs. Bull Amer Math Soc 53:292–294 giving a lower bound on the Ramsey function R(k, k). There is then a curious gap (certainly not reflected in Erdős’s overall mathematical publications) and our remaining papers all were published in a single ten year span from 1955 to 1965.
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