by GaryRussell » Mon Jan 24, 2011 9:24 am
To do this you need to effectively cancel the bet and place it again because Betfair do not provide an option to change both at the same time. The triggers for this are BACKR and LAYR. Use them exactly the same as BACK and LAY, ie. if you are using something like BACK-T1 then you will need to use BACKR-T1 so that the new bet also has a tick offset.