Why did I just skip a division?

You can skip divisions if your MMR is significantly higher than the divisions you are playing in

Does anyone know how this actually works, though? Like, I hear "if you're significantly higher you skip", but I played ranked in Season 4 as a new player and only in offrole since I had a toaster and couldn't call my preferred role, so my MMR was shit. Played this season, skipped B3 to B1, didn't skip to S4, didn't skip to S3, but skipped to S1. So if I'm significantly higher than S2, why would I not skip from the others as well? So far I'm coasting through on S1 games. Way easier than norms imo. Barring outright trolls, it's pretty hard to lose a game unless I play poorly. Just curious on how it all works, since if it thinks I'm significantly higher than S2, why not skip me for the S3/4? I'd be even more significantly higher than them, would I not? I dunno.