Quite plausible. Extreme Value theory [1] appears to have been codified by the 1960s, and one of the main theorems is credited “to Fréchet (1927), Ronald Fisher

Quite plausible. Extreme Value theory [1] appears to have been codified by the 1960s, and one of the main theorems is credited “to Fréchet (1927), Ronald Fisher and Leonard Henry Caleb Tippett (1928), Mises (1936) and Gnedenko (1943)” [2]. ETA: And the second theorem of Extreme Value Analysis is from the mid 1970s. [3] 1. https://en.wikipedia.org/wiki/Extreme_value_theory https://en.wikipedia.org/wiki/Extreme_value_theory 2. https://en.wikipedia.org/wiki/Fisher–Tippett–Gnedenko_theorem https://en.wikipedia.org/wiki/Fisher–Tippett–Gnedenko_theore... 3. https://en.wikipedia.org/wiki/Pickands–Balkema–De_Haan_theorem https://en.wikipedia.org/wiki/Pickands–Balkema–De_Haan_theor...