Anyone can tell me how to calculate cross match odds in two runner markets ?
I like to have a s1backprice, s1layprice, s2backprice,s2layprice based on s_1_backprice vs s_2_layprice etc.
This way I can back or lay based on the best available odds.
I know betfair does automatic cross matching but the autogreenup doesn't work well in two runner markets as it only greens up the selection that was layed or backed and sometimes there is no money above evens meaning that a lay placed below evens doesn't get greened, or gets greened at odds that leaves the book imbalanced.
While I'm at it, what is the formula to green up when a selection has multiple backs and lays ? I know about (bm_backp*back_matched)/lay_price but what if both selections have multiple bets ?
Thanks !