You're right, but with Neptune, they were able to empirically verify that: oh, there's a planet there. Here's they've made the calculations because those (afaik

You're right, but with Neptune, they were able to empirically verify that: oh, there's a planet there. Here's they've made the calculations because those (afaik) fit in the current model and they've concluded: oh, there's (most likely) a planet there. They are only half way there (afaik, but I could have misunderstood their point)