Predicting the Mayoral Election - an alternative approach

A number of years ago now I published my Sweet FA Prediction Model©, an almost infallible method for anticipating the result of a British general election from the result of the previous season's FA Cup Final. If the FA Cup holders at the time of the election are a team who traditionally wear shirts in the Conservative colours of blue or white, ignoring any black stripes, the Conservatives win most seats at the election. On the other hand, if they play in Labour's colours, red and/or yellow, Labour wins.

At the time I first investigated it, this method gave an accurate reading of the result of 11 of the 13 post-war elections which had produced an overall majority. Even more convincingly, in the remaining election – that of February 1974, when no party had a clear win, Labour ending only 3 seats ahead - the Cup obliged by falling to a team whose shirts bear both parties' colours equally, the red-and-white-striped Sunderland. Surely so clear a pattern could not arise purely by chance? And since then, the record is 100%: in each of the last three general elections, the Sweet FA prediction has produced the election winner. (See table). Impressive, no?

* Would have been correct if Brighton & Hove Albion (BLUE) had not missed an open goal in the dying seconds of the FA Cup final, before losing the replay.

But if the FA Cup is so good at predicting general election results, can it do anything else, a colleague asked me this week? And, blow me down, when I looked I found that it has been just as good at predicting the results of the London Mayoral elections since the position was set up: if a team who play in red are the FA Cup holders, Ken Livingstone wins, and if it's a team in blue he loses to his Tory opponent.

With such a tool at our disposal, we only need to remind ourselves that Manchester City won the Cup last year, and we can confidently predict that Boris will win today. There's just one problem. Since the result of an election is such a foregone conclusion once the FA Cup final has been played, doesn't that make all the match reports illegal exit polls in contravention of the Representation of the People Act?

Note for the literally-minded:

I must reluctantly point out that the Sweet FA Prediction model© is not entirely serious. As should be obvious if you read to the end of the original article, it nevertheless had a serious purpose, to point out the pitfalls of assigning undue significance to patterns in past events when there is no reasonable excuse for assuming a causal link, and to distinguish between measurement (what opinion pollsters do) and prediction (what pundits and astrologers do). Those who have been paying attention will have noticed that I subtly amended the interpretation of the data after the 2010 election so as to ensure that the model correctly "predicted" its result. (According to the original model, the Cup should have been won by a team in stripes in 2009, since the 2010 election produced a hung Parliament.) This is what is technically known as "moving the goalposts". And to make the Mayoral prediction work, I've had to "forget" that Ken Livingstone wasn't the Labour candidate in 2000. (I'm not sure what colours the Cup winners ought to wear to predict an Independent win! Perhaps that infamous grey second-strip that Manchester United once sported?)
Too much that passes that for political analysis these days, especially on the Internet, is entirely dependent on reading deep significance into coincidental associations between events. Unless you know why they coincide, that there really is a causal link between the two, such associations may well be meaningless. Much as I love the Sweet FA model, that does not mean that if Plymouth Argyle should win the 2014 FA Cup final I will be expecting to see Caroline Lucas as the next Prime Minister.