I don’t know the exact percent, but a better way to guess this is by the # of rounds of venture investment.
Until you get to Unicorn status, you can roughly assume a board seat is granted to each new lead investor in each round.
And you can roughly assume the founders keep 2 board seats on average.
- So after 2 rounds, control is often (not always, but often) somewhat ‘split’: 2 for the VCs, 2 for founders, 1 for no one / outside director.
- And after 3 rounds — e.g., at the Series C — you can roughly assume the board is controlled, at least nominally, by VCs. 3 seats for VCs, 2 for founders. Maybe 1-2 for outsiders.
There are many exceptions, e.g. Facebook. The exceptions occur when the valuations are high and the term sheets are many. And of course, if you can skip a few rounds, you’ll ask skip these additions to your board.
But I think as a rough rule, after 3 rounds of traditional venture financing — the classic A, B, and C rounds — the VCs hold the majority of the seats, the majority of the board.