User blog comment:D4rkWolf75/Report in, summoners!/@comment-5544574-20140120113553/@comment-5544574-20140120133118

Because it is a soft reset your current MMR affects your placement. Being 6/4 while previously in Diamond II will land you near Gold I / Platinum V while being 6/4 in Silver III will get you around Silver II / Silver I.

There was also something about your first three placement matches being worth more of a 'placement factor' than other games. I think for example, your first three matches affected your MMR placement by 50 points while the remaining seven would net or lose you 20 points.

Basically speaking your provisional result is not tied directly to where you'll be - it is only a deciding factor, albeit an important one, on where you'll be placed.