[2021] Is there hidden mmr in deathmatch?

I'm bronze 2, but my deathmatch games are usually filled with golds and plats and occasionally diamonds and immortals. I usually place somewhere in the top-middle of the scoreboard, but recently I started getting a lot of Immortals and I even had two-three radiants (and a handful of immortals and diamonds) in my two most recent deathmatch games. I rarely see bronzes and silvers, so is matchmaking random and I'm super unlucky or is there some sort of skill-based factor that determines your game? (I'm pretty bad but I don't think there would be 0 silver and bronze players in all of my lobbies)