Our fixtures are
Ross County (10th), Dundee (12th), St Johnstone (11th), St. Mirren (8th), Livingston (7th). So you add up the league positions you get, in our case 48.
Livington have Dundee Utd (5th), Celtic (1st), Hearts (3rd), St Johnstone (11th), Motherwell (6th). So you add them up and you get 26.
The higher the total you have the more teams further down the league you are playing in the run in. The lower the total the more teams further up the league you are playing.
It's simplistic and doesn't take a bunch of factors into consideration but it's just a quick way of comparing each teams run in. We seem to have the easiest one, at least at this point.