Of all the people we've met in the 9 years we've been working on YC, Jessica and I both feel Sam is the best suited for that task. He's one of those rare people who manage to be both fearsomely effective and yet fundamentally benevolent--which, though few realize it, is an essential quality in early stage investing. Sam is one of the smartest people I know, and understands startups better than perhaps anyone I know, including myself. He's the one I go to when I want a second opinion about a hard problem. And his association with Y Combinator is only about a month shorter than mine, because he was one of the founders in the first batch we funded, in 2005. So when Sam became available in 2012, I started trying to recruit him. It took me over a year, but eventually I succeeded.