Yes, but do you mean only the pre-match fav or either player IF they are the fav at the time of the break point?
For the match fav, it just needs the back bet rule applying 'By Position (sorted in Order of Favourtism) 1
That is done on the 'General' tab of the rules editor
https://www.betangel.com/user-guide/app ... tions.html
For the 'Pre-match fav only in addition to the above you need to add a 'Fix order of market selections' rule, and arm it to trigger around the official start time.