The very first annual best-of-the-year anthology series began in 1949, edited by Everett F. Bleiler (SFE) and T.E. Dikty (SFE), the former best known as a bibliographer, the latter as an editor and publisher. Published in hardcover, the series had an irregular run: annual volumes of "Best Science Fiction Stories" from 1949 through 1954, a companion set of "Year's Best Science Fiction Novels" from 1952 to 1954, and then -- under Dikty's editorship alone -- combined volumes of "Best Science Fiction Stories and Novels" for 1955, 1956, and after a year's absence, a "Ninth Series" published in 1958; the last two of these volumes were much slimmer than earlier anthologies, and included stories from each of the previous two years.

The photo below shows 9 of the total 12 anthologies.