Betfair odds vs Max Odds

[missretro]

Hi all. I am doing some backtesting on systems. Using the data from Football Data and the column Max Odds. Would it be safe to assume that the betfair lay odds would be about 5% higher on an average (not counting commission, this is done in the result). So if Max Back Odds would be 2.00, then the lay odds at Betfair would be 2.1 Thanks for any input.

[Matthew]

Re: Betfair odds vs Max Odds I wouldn't say this is a good assumption. The increase on the underdog relates to the odds on the favourite. For my own testing, looking historically, I assume lay odds are max odds + 20%.....very pessimistic. A solution you could try is to find the last price matched in the files at data.betfair.com which would give you an accurate lay odd to work with, although this accuracy comes at a significant cost of your time to work it out. Unless you can find someone who already has the odds.