For each challenge win, whatever their probability of losing was will be added to their overall score. For example, two tribes win immunity, sending the third to tribal council. That would lead to each person in the two tribes gaining 0.33 points because there was a 33% chance of them losing.
I'm just going to add up everyone's total sum, which means players like Joe won't be at the top, despite winning immunity every round until his vote out.
17t. Keith Sowell - 0 points
17t. Reem Daly - 0 points
15t. David Wright - 0.83 points
15t. Kelley Wentworth - 0.83 points
14. Lauren O'Connell - 1.33 points
13. Wendy Diaz - 1.49 points
12. Wardog DaSilva - 1.83 points
11. Aubry Bracco - 2.16 points
10. Victoria Baamonde - 2.49 points
09. Chris Underwood - 2.66 points
08. Eric Hafemann - 2.99 points
07. Joe Anglim - 3.49 points
06. Julia Carter - 3.99 points
05. Ron Clark - 4.35 points
04. Gavin Whitson - 5.09 points
03. Rick Devens - 5.73 points
02. Julie Rosenberg - 5.74 points
01. Aurora McCreary - 5.81 points