Michael Siebel, CEO of YC, offers a controversial take for splitting startup equity: equal equity splits among co-founders. In this video, he shares many reasons why it makes sense to equally split your startup equity.
My personal opinion is to look at these recommendations of Siebel with some perspective because the founders selected at Y Combinator do not appear to me to be a good representation of the majority of startup founders.
My advice for splitting equity is probably controversial, but it's what we have done for all of my startups, and what we almost always recommend at YC: equal equity splits among co-founders.
These are the people you are going to war with. You will spend more time with these people than you will with most family members. These are the people who will help you decide the most important questions in your company. Finally, these are the people you will celebrate with when you succeed.
I believe equal or close to equal equity splits among founding teams should become standard. If you aren't willing to give your partner an equal share, then perhaps you are choosing the wrong partner.