First off, the basics: Our scores are not necessarily a means to measure performance within a season (even though we often treat them as such). Instead, they're an attempt to quantify a Survivor contestant's likelihood of future success, much as predictive stats like WAR do in baseball. Essentially they assess: How likely is this contestant to win the next time they play Survivor? (Assuming no drop-off in performance over time). The theory is as follows:
The ideal Survivor contestant should have all three "tools" required to play: (1) challenge ability (easiest to quantify, just by counting wins), (2) social ability, and (3) strategic ability. The last two are difficult to measure, but both are reflected in a couple of measurable ways: tribal council performance, and receiving jury votes. Tribal council performance: A good strategic player will guide the vote in such a way as to (almost) always know, and vote for, the person that gets booted. Similarly, part of a good social game is being sufficiently in the loop to do the same thing. Conversely, a good social player should rarely receive votes against him- or herself (and it makes no strategic sense to receive lots of votes against, either). Getting voted out is not good strategy. Jury votes: The ultimate test of both strategic and social prowess is, of course, being able to convince the jury to award you the million dollar prize. So jury votes are, despite the small sample size, fairly important.
To put all this together, we created the Survival Average (SurvAv).
It's a simple sum of fractional Challenge Wins (ChW), weighted TC Ratio (wTCR), and (eventually) a weighted Jury%. This has two advantages over SurvSc, measured below: (1) It's always a positive number (or zero), since tribal council votes are treated as a weighted ratio (instead of a potentially negative sum), and (2) it has a larger spread, and in looking at past seasons, we just feel it better represents the games we saw. As such, we've ordered the contestants based on this number in the table of complete Season 15 totals.
Our other metric, which we less favor, is the Survival Score (SurvSc). It's simply the sum of three components, expressed as percentages: Challenge Win% (ChW%), Tribal Council% (TC%), and Jury Vote%. So Survival score = ChW% + TC% + JV%, for a max score of 2 (3 after the finale).
Neither ranking is perfect, however, and we're open to suggestions. Feel free to comment below with potential improvements. We're keeping both scoring systems active through this season to see how they shake out.