Expected value is such a foundational concept in the River’s way of thinking that 2016 served as a litmus test for who in my life was a member of the tribe and who wasn’t. At the same moment a certain type of person was liable to get very mad at me, others were thrilled that they’d been able to use FiveThirtyEight’s forecast to make a winning bet. (I still sometimes get poker players picking up dinner tabs for the money that my forecasts made them in 2016 or other years.)
