Hi
selection index is the order of selections as displayed by Betfair. You are correct sometimes the index is not the same in some markets, but you can adjust your conditions to take that into account. In your first post you asked about betting the same selection in the Half Time market if a bet has been placed in the Match Odds market. Now the index numbers are always the same in those two markets:
1 = Home Team
2 = Away Team
3 = The Draw
another way to do the HT / MO is:
markets betting code is Half Time (Soccer)
AND
OR
selections trigger expression football1_s_1_back_matched is greater than 0
and selections trigger expression sel_id is equal to football1_s_1_sel_id
OR
selections trigger expression football1_s_2_back_matched is greater than 0
and selections trigger expression sel_id is equal to football1_s_2_sel_id
The method is the same if you want to bet in Next Goal if a selection has a matched back bet in Match Odds:
markets betting code is Next Goal (Soccer)
AND
OR
selections trigger expression football1_s_1_back_matched is greater than 0
and selections trigger expression sel_id is equal to football1_s_1_sel_id
OR
selections trigger expression football1_s_2_back_matched is greater than 0
and selections trigger expression sel_id is equal to football1_s_2_sel_id