That's a great question. We don't look at a single success rate; we look at a wide variety of success rate metrics. It's important to point out (thanks @ferre

That's a great question. We don't look at a single success rate; we look at a wide variety of success rate metrics. It's important to point out (thanks @ferrelty) that there are many forms of success itself. A company that takes an early acquisition for $2M, or a company that becomes a profitable life-style business, won't make YC much money. But it may be life changing for the founders and a big success for them. We like to consider those companies successes, and tons of YC founders choose paths like that and we always support them. There are other kinds of success too - YC funds nonprofits, and when those are successful, we don't get any return at all but we think it's very valuable and important. Still, from the standpoint of YC's business model, we need at least some companies to get big in order to make our organization sustainable. In this case, the "success rate" metrics I was referring to are more that narrow financial kind - the question of whether the same percentage of companies are on track to become big successes. We measure that by comparing each batch to prior batches, adjusted for time. So for example, if we're looking at the W2016 batch now, we want to compare it to the W2011 batch as it looked in February 2014. We compare batches in lots of ways: fundraising and valuation, revenue, profitability, growth rate, exits.