Of the last 22 games I've played, i've played 13 top games, and 9 mid games.
Mid is my primary role, top is my secondary - and that's how i enter every queue.
Of those games, 1 top game I was autofilled jungle, and negotiated my way to top lane. Also, at least 3 of those mid games, I was put in top lane and negotiated my way to mid.
All in all, of the last 22 games the algorithm has put me in my secondary role 15 times, autofill once, and my primary role 6 times.