For Euro 2008 I tracked the odds of any of the teams winning over time. It makes a kind of fun graph:
The y-axis shows the odds (screen scraped from a betting web site… not doing that again), converted into a probability, and multiplied by 16. Why multiplied? To give a kind of “value” to each team: if you’d purchased a team for £1 in a sweepstake, then you can plot a kind of value for it over time by multiplying the odds of winning by the size of the pot (£16). Kind of.