I'm A Doctor As Well, You Know. Doctor Too, Is What I'm Saying.

With tomorrow being D-Day for those excited about newly rediscovered Doctor Who episodes - a group that most certainly includes me - I have a golden opportunity to bust some basic probability out on y'all.  What are the chances of either finishing a partly-complete story, or of unearthing an episode from an entirely absent story?

If we ignore "Mission to the Unknown" (this was Abi's idea, so complain to her if you don't like it; personally I went for it mainly because it simplifies the maths), there are nine entirely absent stories.  There are six stories missing two episodes, and one story ("The Tenth Planet") missing one.  The BBC have referred to missing episodes, plural, so if we take the worst case scenario, the chances of completing a full story are around 2%, and the chances of seeing part of a hitherto entirely unavailabe story rests at 60%.

But maybe things are less bleak.  Maybe the BBC found three episodes.  At that point, we're looking at a 3% chance of a complete story, and a 74% chance something entirely new has turned up.

Except, though, that those calculations assume independent finds, which seems pretty unlikely. Multiple finds don't necessarily mean episodes from a single story, but that's a definite possibility (see "Cybermen, Tomb of"), and the contrary idea - finding an episode from one story means the next find is actually less likely to come from that story - seems on its face to be foolish.

That means we can treat the figures for the probability of a complete story as minimum values, but the probabilities of "new" stories as maximums.

Anyway, here's the results of a few hours noodling during a day of boring talks:

(Apparently there might be as many as nine unearthed episodes, but I ran out of talks.)

Cheers to tweeps Abi, JJ, and Fonz for helping me out with the numbers of missing episodes/stories whilst I was out of reach of my laptop.