Probability Zero
from Fancyclopedia 2 Supplement ca. 1960
A department on Astounding Science-Fiction during the first half of the '40s, given over entirely to the elaboration of tall stories by veteran pros and ambitious fans. Payment was made for the best story of the issue, as determined by reader response. These extremely compact, anecdote-humor stories were very likely a major influence on modern fanfiction, as examples of science-fantasy anecdotes — which is, essentially, what modern fanfiction is. Stories of this type are so much easier to write well for the space limitations of a fanzine that the earlier type of fan fiction — i.e., fan-written imitations of professional serious work — has become practically extinct.

Note that the Probability Zero department was later revived in ASF.