Mid-Season 2012-2013 EPL Prediction Contest Update

As an exercise in humility and illustration of the concept of skill in forecasting I have run a few small prediction contests here over the past few years. We are just past mid-season in the Premier League which provides a good excuse to see how things stand in that contest.

Here are the mid-season standings of the 10 participants:

Elijah	15.4
Megan	15.9
SKILL	16.4
itzik	17.8
n-g	18.0
dave tombs	20.2
Calvin	20.8
Pielke	23.3
keeperusa	23.3
Arthur	24.0
Max	24.7

The numbers above represent the square root of the sums of the mean-squared errors in the predicted standings. The biggest collective errors: West Brom (picked too low) and Newcastle (picked too high). Smallest errors: Man City, Man U and Reading.

What does this exercise tell us? The most important lesson, one that is learned in many walks of life, is that a naive prediction methodology can be very hard to beat. Only two entries are running ahead of an entry based on last year's final table.

The far more difficult question to answer, and one with an answer that has a lot of significance to decision making in areas far more important than sports prognostication -- are those 2 skillful entries showing skill because the forecasts had skill, or just luck?

For a discussion, see this post on hot hands and guaranteed winners.