How did I get Onyx in FFA?

Last night I played my 10 placement matches in FFA.

The first game I played I played well and got 1st fairly easily. This game was against a few gold players and a few platinum. I could tell through out the rest of my 9 remaining placement matches that the players I was matched against were a bit better than me, and really I wasn’t playing that well. After the matches I kept checking and I was being matched up with onyx ranked players (this was the case for every game except the first).

Here’s a breakdown of my 9 matches against mostly onyx players and a couple diamond:

Placed 7th (5 games)
Placed 6th (1 game)
Placed 5th (1 game)
Placed 4th (1 game)
Placed 2nd (1 game)

To my surprise, after I finished my last match, I was placed in the onyx tier. My question is, if the ranking system is based off of wins/losses… how in the hell did I land in the onyx tier for FFA?

In team arena (the only other playlist I’m ranked in) I am platinum, and I feel like that is a good spot for me. I’m a good player, especially considering I don’t play very often. But onyx? I won’t get stomped on, but it is probably going to be uncommon for me to win a game since I feel like it’s a bit above my skill level. The only conclusion I can come to is the ranking system is messed up for FFA and lots of people are being placed in onyx? I don’t know, it seems weird to me.