Success “rate” is the wrong metric. The earlier stage you invest, likely, the more 0’s in your portfolio.
However, my understanding is that Lowercase I (Chris Sacca) is > 200x with Twitter, Uber, Instagram, Docker, etc. and is widely believed to be the best performing Tiny Fund ($8m).
I haven’t seen the data, however.
Whatever the exact data, it looks like it’s the best of all time from a multiple perspective.