Bill Sandholm (1970-2020)

The evolutionary game theorist Bill Sandholm has left the game.

Here's the memoriam from the Game Theory Society:
In Memoriam: William H. Sandholm (1970-2020)

And here's the obit from the Department of Economics at the University of Wisconsin, where he spent his career. It lists the cause of death as depression.
In Memoriam: William H. (Bill) Sandholm, leading evolutionary game theorist, cherished mentor and valued colleague

Here's his home page at the University of Wisconsin: Bill Sandholm's Home Page
Here's his Google Scholar page: William H. Sandholm