THETAB.COM - Nov 20 - Tinder's algorithm uses its very own "desirability" ranking, called an "Elo ranking" which pairs people. Every user has a rating on Tinder, and they can only swipe through people of a similar rating. If users have low ranking, they'll see people with low rankings too. The rating is technically not a measure of attractiveness, but a measure of "desirability," according to Sean Rad, founder and former CEO of Tinder. "It's not just how many people swipe right on you," he said. "It's very complicated. It took us two and a half months just to build the algorithm because a lot of factors go into it."