Hi
it depends when you want to place the bets (ranks can change frequently)
you can use a formula like this in the amount field :
IF(sel_order = 1, 10, IF(sel_order = 2, 11, IF(sel_order =3, 12, 13)))
or
use 3 separate triggers, one for each rank and amount:
amount: 10
condition: selections rank is equal to 1
once per market
amount: 11
condition: selections rank is equal to 2
once per market
etc...