in general, the median's around 6% and i think is also the most common, and i didn't encounter anyone who had negotiated it down. i don't think there's a formula. we had a working demo, and thousands of lines of code, but got the same deal as other groups who just had an idea.
unless the % seems way out of kilter, it's probably not worth optimizing this or cutting yc down (after all, they're making rapid fire phone calls down a list of people who would gladly take your spot. things like your option pool and follow on investments will be the dominating factors in your dilution anyway.) they definitely earn their chunk, and contribute _vastly_ more than the equity they take, even at the highest end.
unless the % seems way out of kilter, it's probably not worth optimizing this or cutting yc down (after all, they're making rapid fire phone calls down a list of people who would gladly take your spot. things like your option pool and follow on investments will be the dominating factors in your dilution anyway.) they definitely earn their chunk, and contribute _vastly_ more than the equity they take, even at the highest end.