There have been some interesting threads started by Jonathan Chance on election predictions (such as here and here).

Let’s assume we take only the top 3 predictions for each poster (to keep the maths simpler.)

For example, we could have predictions like these examples for Iowa:

Poster A

Trump 38%

Cruz 20%

Rubio 15%

Poster B

Cruz 30%

Trump 25%

Bush 20%

The actual result was:

Cruz 28%

Trump 24%

Rubio 23%

So we can make a formula for each poster’s prediction based on (say):

- the difference between predictions and actual for the top three candidates (always take as positive)
- a ‘penalty’ for each top three candidate missed (I’ll use 25%)
- then take the total of the above two and subtract from 100 (just to give a positive result)

Using my formula, the above two predictions would score:

100 - (14+8+8) = 70 for Poster A

100 - (2+1+25) = 72 for Poster B

So B does slightly better, despite missing one of the top 3.

What do you think of my formula?

Have you got a better one?!

If I get enough interest, I’ll have a go at ranking the posters for each State.