Originally Posted by
You want to go where?
I agree that the likelihood grows smaller the larger the number is, but I do know a couple where each of them has three citizenships, none of which coincide. Four of those six total citizenships were acquired after birth (that is not from their parents). They both currently live in yet another country, so that if they have a child in that country (a jus solis country), the child has the potential for 7 nationalities. But just imagine if those two people had parents from two different countries - that would have added another two potential nationalities for 9!
I've met people who were at birth born with a right to 4 ordinary citizenships, but I've met none that I knew were born with a right to at least 5 although it does exist. Ending up with more than 5 by means other than by right of birth does exist, but that seems to be more likely than inheriting more than 7.
I wouldn't be shocked completely if right of birth may convey 9 citizenships as you mention, but I'd love to see any combination of countries where that is possible and the legal pre-reqs applicable to parents and/or child got navigated so as to make that realized. The inherent sexism or xenophobia in a lot of acquisition/retention/transmission citizenship-related laws increases the complexity the more countries are involved.