Further to my previous theory...

...some of you may be aware of my thesis that authors born between 1942 and 1951 (inclusive) have won a surprisingly large number of Hugo and Nebula awards. I have done a bit more number-crunching on this question.

We know the age profile of Hugo and Nebula award winners; we know how many works written in each year have won awards; so we can calculate how many awards for works written in each year should go, on average, to the age cohort of those born between 1942 and 1951, if they won awards at the same average rate as authors born in all years, and compare that with the actual numbers of awards won for works written in each year by authors born between 1942 and 1951. The results are startling:



(I should clarify that the years tabulated are the year of publication of the award-winning work, and that I tally each joint win separately - so the joint win by Mr and Mrs Robinson of the 1978 Hugo and 1977 Nebula for "Stardance" counts for four awards in 1977, the year of publication.)

There have been four years when the 1942-51 cohort managed a clean sweep of all Hugos and Nebulas for works published in that year:

1983:
Gardner Dozois (b. 1947) Nebula, Best Short Story, "The Peacemaker"
Octavia E. Butler (b. 1947) Hugo, Best Short Story, "Speech Sounds "
David Brin (b. 1950) Hugo & Nebula, Best Novel, Startide Rising
Greg Bear (b. 1951) Hugo & Nebula, Best Novelette, "Blood Music"; Nebula, Best Novella, "Hardfought"
Timothy Zahn (b. 1951) Hugo, Best Novella, "Cascade Point"

1984
John Varley (b. 1947) Hugo & Nebula, Best Novella, "Press Enter "
Octavia E. Butler (b. 1947) Hugo & Nebula, Best Novelette, "Bloodchild"
Gardner Dozois (b. 1947) Nebula, Best Short Story, "Morning Child"
William Gibson (b. 1948) Hugo & Nebula, Best Novel, Neuromancer
David Brin (b. 1950) Hugo, Best Short Story, "The Crystal Spheres"

1988
C.J. Cherryh (b. 1942) Hugo, Best Novel, Cyteen
Michael D. Resnick (b. 1942) Hugo, Best Short Story, "Kirinyaga"
Connie Willis (b. 1945) Hugo & Nebula, Best Novella, "The Last of the Winnebagos"
George Alec Effinger (b. 1947) Hugo & Nebula, Best Novelette, "Schrödinger's Kitten"
James Morrow (b. 1947) Nebula, Best Short Story "Bible Stories for Adults, No. 17: The Deluge"
Lois McMaster Bujold (b. 1949) Nebula, Best Novel Falling Free

1992
Vernor Vinge (b. 1944) joint Hugo, Best Novel, A Fire Upon the Deep
Connie Willis (b. 1945) joint Hugo and Nebula, Best Novel, Doomsday Book; Hugo & Nebula, Best Short Story, "Even the Queen"
Janet Kagan (b. 1945) Hugo, Best Novelette, "The Nutcracker Coup"
James Morrow (b. 1947) Nebula, Best Novella, "City of Truth"
Lucius Shepard (b. 1947) Hugo, Best Novella, "Barnacle Bill the Spacer"
Pamela Sargent (b. 1948) Nebula, Best Novelette, "Danny Goes to Mars"

That's probably not going to happen again. They did not win any awards for works published in 2000, for the first time since 1973. Since then, however, they have won another 13, whereas if they won at the average rate of all authors, they would have garnered only another 6.83.

In summary: authors born between 1942 and 1951 have won almost twice as many Hugos and Nebulas as might be expected, comparing them with all Hugo and Nebula winners.