Will Cameron Go? Using #Clojure, betting odds, Sherman Kent and probability.

I don’t trust social media hype. Simple as that, while internet is the perfect platform for saying how you feel that’s no guarantee that action will take place.

Cameron Will Be Gone Tomorrow(?)

So when I see things like this:


It’s not my default thought to think that’s that, it’s a done deal. No way, never, nope not me.

There is a Better Gauge

Twitter with it’s automated tweets and “let’s see if we can get this trending” is something I certainly don’t trust. It’s not a gauge of X-Factor or The Voice winners so I don’t really give it much hope for anything else these days.

Edward Snowdon on the other hand did hit the sentiment right.


An even better gauge on predicting the future is to see who’s putting real money on it.

Show Me The Odds….


And low and behold, there’s a couple of open books on when David Cameron will no longer be Prime Minister. For him to leave in 2016 there are two odds 2/1 and 7/4.

Betting odds are just another way of showing probability. Easy worked out too. So 2/1, we can call A = 2 and B = 1, A/B. To work out the percentage probability of those odds as % = B / (A + B).

I can even wrap that up in a Clojure function:

(defn calc-prob [a b] (double (/ b (+ a b))))

So Ladbrokes are giving us 2/1, let’s have a look with my new function.

user> (calc-prob 2 1)
;; => 0.3333333333333333

So 33% chance…. ok, let’s look at Betfair at 7/4.

user> (calc-prob 7 4)
;; => 0.3636363636363636

Let’s Consult Sherman Kent

Sherman Kent retired from the CIA in 1967, one of his legacy’s though was a chart, a real simple one, on the potential outcome based on a probability. A “fair chance” of success was defined as 3 to 1 against success by an advisor, Kent needed a way of interpreting what “fair chance” and words like “probable” were from advisors, so he came up with this table.

Certainty (%) General Area of Possibility
100% Certain
93% (+/- 6%) Almost certain
75% (+/- 12%) Probable
50% (+/- 10%) Chances about even
30% (+/- 10%) Probably not
7% (+/- 5%) Almost certainly not
0% Impossible

So looking at our 33-36% betting probability of Mr Cameron packing up in 2016, it’s looking as a “probably not”.

To Summarise

When people put money on things they have a certain confidence that the event is going to happen. That sorts out the serious folk from the armchair opinions straight away. So it’s a good idea to consult these odds to see if they agree or disagree with the hypothesis. It’s just another piece of information.

Thrown in with a quick Clojure lesson, betting probability and a history lesson on Sherman Kent, well that’s not a bad evening’s work.


2 responses to “Will Cameron Go? Using #Clojure, betting odds, Sherman Kent and probability.”

Leave a Reply

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

WordPress.com Logo

You are commenting using your WordPress.com 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

This site uses Akismet to reduce spam. Learn how your comment data is processed.

%d bloggers like this: