As you know Euro 2012 is a seeded tournament. When the little balls came out of the bag it was designed so that the higher ranked teams would progress to the latter stages of the tournament and make UEFA more money, sorry, make the tournament more entertaining.
To be fair to UEFA, it is the same in most modern tournaments, the big teams and big audiences fund the sport and therefore want to be favoured. Tennis grand slams are seeded for the same reason. People want to turn up in the mens final to see Federer, Nadal and Djokovic in titantic battles. Not an error strewen battle between rank outsiders who fluked their way to the final.
The characteristic you see in seeded tournaments, rather obviously, is that the favourites do tend to progress. If you dutched the top three teams at Euro 2012 they started the tournament accounting for 56.1% of the book, after the first round that has increased to 57.1%, then 65.5% by the quarter final stage.
If you felt exposed on this, bearing in mind the third favourite was France, you could cover the top five. The figures would have read, 66.2%, 72.5% and 75.5%. Basically you would have returned 9.3% on your stake.
There are variations on this and each type of tournament has a ‘sweet spot’. But it’s a neat way to expose yourself to upside potential while limiting downside.