When I was a kid, I read somewhere that the ratio of twins to single births was something like 1:83, and the ratio of triplets to twins was the same.

I found this really striking. What a coincidence... right?

Well, today I'm not convinced we have numbers as precise as that factoid suggests. But this one mechanism is responsible for like 2/3 of cases of multiple births, and it kinda predicts the proportions would be the same. Each extra dominant follicle is an independent event.