Watching the odds

I tracked some prices of the England v Spain friendly football international yesterday. Betfair provide an open access API and some sample code that is easily modified to watch the price data over time. Spain were favourites and England were expected to struggle. In the end England despite missing some big names were resolute and saw out the Spanish pressure, managed to score a set piece goal, and held out for the 1-0. This had better not make them favourites for Euro 2012!

First of all stake over time:

My graphs are per minute, with about 30 minutes pre match included. A staggering £8 million changed hands! Next the bets for the home win with implied percentage (interestingly Betfair call the outcomes "runners" in their sample code, betraying their horse betting roots):

The Lampard goal clearly evident, England were drifting as time went on - the market reacting to their dogged defensive work.
The draw as implied percentage:

The away win as implied percentage, you can see Spain throw it away...