What? My KDR is a little above 3 and I get grouped with people struggling to have .50 KDRs. It doesn't search for similiar stats, matchmaking is just ****.
If you're the only 3 kdr in a lobby and the two next best guys have 1.5 and everyone else is below 1.0?
It's a forgone conclusion that those two guys will be one the same team and not on your team.
Assuming the lobby is completely randoms.
KDR, though, is not the only thing the game considers. In fact, I'm 90% sure that none of the stats are weighted, only the teams that are created are weighted. The thing is, most of the time a player's other stats are going to be similar to his/her kdr.
You tell me the kdr of 12 random players that were in a match and you will be surprised at how accurately I can predict what the teams will be.
Not really. See, this is exactly why I say that if you have a high KDR when you mostly play with a party that you're going to be upset when you play solo. Stats from playing in a party are fluffed.
Look at it this way. The rule of thumb is that all the odd ranked players in the lobby will be on one team, the evens on the other. By rank, I mean rank IN THE LOBBY, not in the overall community. i.e., you're the fifth best player in a lobby? You'll be on the same team as the best player in the lobby.
The problem is that the # 10 and #12 players might have had a lucky match and now they are ranked # 9 and # 11 in the lobby. If you're still ranked # 1 - and most likely you are - you get stuck with the worst guys in the lobby.
This way of weighting is even more obvious when you have guys with ~2.0 or higher KDRs. The higher your kdr and the greater the difference between your kdr and the next best player's kdr, the more likely you are to get the scrub players on your team.