Ranked Play - Provisional Rank After 1st Game

Hi Guys:

Just curious do I get placed B4 if my first Ranked game is with a B4 Ranked Player?

Should I rather play alone for all placements? I was S4 last season but I played my 1st ranked game with a B4 player and got placed B4, and my provisional rank for winning 1st game is B4 :(.