The dirty secret is that, despite what they may claim, venture capitalists aren’t good at picking winners, nor do they need to be.
The real skill is in (a) raising funds from LPs, and (b) creating a wide enough deal funnel to service it.
The individual investments aren’t that important, just like a single bet doesn’t matter when you’re playing poker. It’s more about spreading the money over as many hands as possible and letting your mathematical advantage do the rest.