What % of YC companies were "pro"
pg: You mean which have some kind of post-school work experience?  Certainly the majority.  Maybe 80%.  Though interestingly some of the biggest successes (e.g. Loopt, Dropbox) were started by people straight out of school.Young founders have more variance.  They often flame out, but when they don't they often do really well.  For that reason we've made a conscious effort not to get conservative and fund only startups that seem safe.When we first started, we had no choice but to fund risky startups, since those were the only ones that applied.  Now that we're better known we get a lot of applications from older, more legit seeming founders.  It would be easy to start funding only them and ignoring the 20 year olds, but that would be a mistake. The median 20 year old is going to fail, but the best one is Sam Altman.