If chess.com were a country it would be the 8th most populous in the world with around 205,000,000 users.
But co-founder Danny Rensch's story isn't your typical Silicon Valley success story.
He grew up in rural Arizona in a religious cult, where his talent for chess was preached as a divine "purpose."
He was pushed hard, both celebrated and controlled. By his twenties, he had won national titles and achieved International Master status, but was also a high school dropout, deep in debt, battling panic attacks and alcohol addiction.
He also had a vision: to make the game to be as accessible and rewarding as possible.
His new memoir Dark Squares tells that story: the cult years, the dark years, and the revolution that has changed the game.
