Building the Nebula Model, Part 4

This post continues my discussion on building my 2015 Nebula Best Novel prediction. See Part 1 for an introduction, Part 2 for a discussion of my Indicators, and Part 3 for a discussion of my methodology/math.

Now to the only thing anyone cares about: how reliable is the model?

Here’s my final Nebula prediction from 2014:

1. Ann Leckie, Ancillary Justice (25.8%) (winner)
2. Neil Gaiman, The Ocean at the End of the Lane (20.7%)
3. Nicola Griffith, Hild (11.2%)
4. Helene Wecker, The Golem and the Jinni (10.6%)
5. Karen Joy Fowler, We Are All Completely Beside Ourselves (9.8%)
6. Linda Nagata, The Red: First Light (8.2%)
7. Sofia Samatar, A Stranger in Olondria (7.7%)
8. Charles E. Gannon, Fire with Fire (6.0%)

As you can see, my model attaches % chances to each nominee, deliberately avoiding the certainty of proclaiming one work the “sure” winner. This reflects how random the Nebula has been at times. There have been some true left-field winners (The Quantum Rose, for instance) that should remind us statistical certainty is not a possibility in this case.

Broadly speaking, I’m seeking to improve our sense of the odds from a coin-flip/random model to something more nuanced. For 2014, a “coin-flip” (i.e. randomly picking a winner) would have given a 12.5% chance to each of these 8 nominees. My prediction doubled those odds for Leckie/Gaiman, and lessened them for everyone else. While that lacks the crisp assurance of “this person will definitely win,” I think it correctly reflects how variable and unpredictable the Nebula really is.

A fundamental weakness of my model is that it does not take into account the specific excellence/content of a book. I’ve done that deliberately. My thought process is that if you want analysis/forecasts based on the content/excellence of a book, you can find that elsewhere on the web. I want Chaos Horizon to do something different, not necessarily imitate what’s already being done. I don’t know how, in the more abstract/numerical terms that Chaos Horizon uses, to measure the relative quality of a Leckie versus a Gaiman. I don’t think Amazon or Goodreads measures quality in a compelling enough fashion to be useful for Chaos Horizon, although I’m happy to listen to counter-arguments.

Even if we could come up with an objective measure of quality, how would we correlate that measurement to the Nebulas? Some of my indicators do (either directly or indirectly) mirror excellence/content, but they do so at several removes. If a book gets lots of nominations, I’m accepting that SFF readers (and voters) probably like it. If SFF readers like it, it’s more likely to win awards. Those are pretty tepid statements. I’m not, at least for the purposes of Chaos Horizon, analyzing the books for excellence/content myself. I believe that an interesting model could be built up by doing that—anyone want to start a sister website for Chaos Horizon?

Lastly, I’ve tried to avoid inserting too much of my opinion into the process. That’s not because I don’t value opinion; I really like opinion driven web-sites on all sides of the SFF discussion. Opinion is a different model of prediction than what I use. I think the Nebula/Hugo conversation is best served by having a number of different analyses from different methodological and ideological perspectives. Use Chaos Horizon in conjunction with other predictions, not as a substitute for them.

I posted last year about how closely my model predicted the past 14 years of the Nebulas
. The formula was 70% successful at predicting the winner. Not terrible, but picking things that have already happened doesn’t really count for much.

I’ll wrap up this series of posts with my “To-Do” list for the 2015 Nebula Model.



2 responses to “Building the Nebula Model, Part 4”

  1. Charles Gannon says :

    Very interesting and very informative. By the way, have you ever seen the actual rankings? They are available through SFWA on the site. I could provide them. BTW, Fowler came in 2nd, Gaiman and I tied for third, although, having more nominations, that breaks a tie for winners.

    • chaoshorizon says :

      Fascinating. The current model has definite trouble picking up debut novels unless they show up on other awards or year-end lists. I also think it’s underselling more traditional SF; maybe I need an indicator that boosts that specific sub-genre. All in all, this year’s model should do a better job with Trial by Fire given last year’s Nebula.

      I’m always interested in looking at any kind of data! My e-mail over here is

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

Xeno Swarm

Multiple Estrangements in Philosophy and Science Fiction


Pluralism and Individuation in a World of Becoming

Space and Sorcery

Adventures in speculative fiction

The BiblioSanctum

A Book Blog for Speculative Fiction, Graphic Novels... and more!

The Skiffy and Fanty Show

Running away from the thought police on wings of gossamer and lace...

Relentless Reading

"A Veritable Paladin of Blogging!"


A little about me, a lot about books, and a dash of something else

Far Beyond Reality

Science Fiction and Fantasy Reviews

Andrew Liptak

three more from on high

Eamo The Geek

The Best In Sci-Fi And Fantasy Book Reviews by Eamon Ambrose

Read & Survive

How-To Read Books

Mountain Was Here

writing like a drunken seismograph

The Grimdark Review

The very best of fantasy.

SFF Book Reviews

random thoughts about fantasy & science fiction books

Philip K. Dick Review

A Re-read Project

Notes From the Darknet

Book reviews and literary discussion

%d bloggers like this: