(I hope I understand virtual odds. I do understand back/lay concept)
For the sake of simplicity, take a tennis event. We have two runners A, B and for both we have back and lay offers, so we are dealing with 4 price lists of offers.
Thanks to the virtual odds, if we exclusively monitor and analyze back A and back B offers, all the offers on the lay A and lay B will be available as virtualized odds within the back A and back B offers (transformed by Betfair's virtualization algorithm respectively, lays on B will be transformed as back A with the appropriate odds and amount, etc).
The same true for the lay offers: the lay A and lay B offers virtually include all the back offers transformed, virtualized
Am I missing something? My conclusion is, that analyzing the 4 price history is redundant, having virtualized odds included, it is enough to analyze backs, all the market lays information included. After virtual odds included, only two informational odds time series are necessary for strategy analysis:
- back A and back B (preferably, but the following three will do it also:)
- lay A and lay B
- back A and lay A
- back B and lay B
...again, am I missing something, or can my observation be confirmed?