Hi
football1_ = match odds
r_1_ = rank 1 (fav)
sel_id = selections unique ID in
BetFair's database
s_1_ = selection index 1 (home team in MO markets)
if you put them together, the condition is saying:
in match odds market the favourite's ID is equal to home team ID
this is your first stipulation for your trigger (home favourite)
and this condition checks the home team is indeed the favourite
the next condition in the trigger then determines the home favourite price is greater than 2.0