I'd expect finger length and even ratio between them to play an important role. I was talking with a friend about how he had issues reaching some keys which se

I'd expect finger length and even ratio between them to play an important role. I was talking with a friend about how he had issues reaching some keys which seem easy to reach for me. And I don't think I have particularly big hands, I can't reach any F key if my fingers are on the home row. I can barely reach 4 and 8, but it's uncomfortable.