I was playing my placement matches on swat, where I proceeded to win 9/10 games, have a accuracy of 37.7, and about a 2.0 KDA while maintaining a 1st or 2nd position on the leader board. When I finished my 10 games I found myself in Platinum 4, and that makes absolutely zero sense because 343 has stated that only wins count towards your rank, so how does winning 9/10 matches give me platinum 4?
I had the exact same issue, won 10/10 games in team arena, placed plat 4.