YC is an investor, putting money into lots of startups. As a result, it benefits from the law of large numbers (https://en.wikipedia.org/wiki/Law_of_large_numbe

YC is an investor, putting money into lots of startups. As a result, it benefits from the law of large numbers (https://en.wikipedia.org/wiki/Law_of_large_numbers https://en.wikipedia.org/wiki/Law_of_large_numbers), so luck isn't as big a factor as it is for individual startup founders.