When did Gandalf Choose Bilbo?
 

This question is the end result of a long train of thought. I was looking into the intervening years between the fall of Erebor and the quest. I know they ended up in the Blue Mountains for a while but Thorin, in particular, never gave up the thought of taking it back.

So a bit of Yada Yada Gandalf gets the key and map decides on burglary and just seemingly decides on a Hobbit and Bilbo in particular. The thing is he chooses Bilbo(seemingly) in the morning and that evening the dwarves arrive. Gandalf must’ve already settled on Bilbo, or the very least a Hobbit(and Bilbo specifically seeing as the dwarves all go directly to BagEnd) and had the dwarves already on the way. I’m reminded of Gandalf keeping Beorn busy with a story slowly marching the dwarves up two by two, they arrive to Bilbo’s in a similar fashion just a couple at a time and he lets them in he probably would have more forcefully reject 13 at once, it seems a very Gandalf arrangement.

So the question after that ramble when did Gandalf settle on Bilbo?

The Unfinished Tales section The Quest of Erebor addresses this question.

The scene is that of Gandalf telling Frodo, Merry, Pippin, and Gimli in Minas Tirith about the events leading to The Hobbit

Gandalf goes on to say that when he entered the Shire after speaking with Thorin, he heard Bilbo was still unmarried, and was known to do odd things like talking to Dwarves.
It was then he decided to send a hobbit with Thorin and Co., and to make that hobbit Bilbo.

In another version, Gandalf is said to have wanted a hobbit with 'a dash of the Took', and a 'stolider' family like Baggins. That also led to Bilbo.

Most excellent. I read UT long ago and certainly have no memory of that. And perhaps I didn’t google properly because it didn’t come up.

Inzil has already answered the question (I always think of how big a shock Gandalf must have had when he found that Belladonna Took's son now resembled a grocer more than an adventurer!), but I just wanted to pick up on this:

I remember clearly that the Unexpected Party isn't the same day as Gandalf showed up, but in my head it was several days later. I have a distinct memory of Bilbo suggesting "next Wednesday", but nope - he actually says "Come tomorrow!" So it was about a day and a half from "Good morning!" to "Dwalin at your service."

Looking through UT, it seems that (in an earlier version of the draft text) the dwarves were staying down at Bywater - presumably at the Green Dragon, given they meet Bilbo there afterwards. I have to wonder whether Gandalf actually when back to see them once he'd discovered just what Bilbo had become, or whether he sat outside brooding somewhere that Thorin couldn't find and interrogate him.

(Perhaps he rode out to visit the new Thain Fortinbras and his domineering wife Laila.)

hS