One of my favourite evening reading sites is TV By The Numbers and Bill Gorman’s Renew/Cancel Index.

Bill uses ratings to build a predictive index – all based on the insight that you don’t have to outrun the cancellation bear, you just have to outrun the other guy! By comparing a set of ratings against the network average, Bill can deduce which shows are likely to be renewed, on the bubble, or cancelled.

The usefulness of a predictive algorithm is in how accurate the predictions are.

And I’d say that his index is pretty predictive. Excluding renewals and taking his index value of.90 as the cutoff for renewal or cancellation, his model yields 95% precision and a 77% recall.

The index is better at predicting if shows will be renewed than it is at predicting cancellation, however, 77% recall really isn’t bad.

(We’re talking about imperfect executives making imperfect decisions, we’re not talking about chemicals predicting the presence of other chemicals in a sample.)

That’s pretty neat isn’t? And the site is pretty useful too. Thanks Bill!


I’m Christopher Berry.
I tweet about analytics @cjpberry
I write at