WotLK SoloQ MMR drop/win logic

[stoyooo]

Wanna ask what is the logic for the MMR drop for the shaman on that image:
https://imgur.com/ijPfKO3

As you can see, his teamates are with much lower MMR. The enemy team is much closer to the shaman MMR.
But his MMR drop is like he is losing from enemy with the same MMR like his teamates.

Can someone tell how the things are calculated.

[skullatbash]

Shaman have lost -13 mmr/personal (as he faced enemies close to his mmr, which is true)
His partner have lost way less.

Why do you think there is something wrong ?

[Razerx]

Because he is playing with less geared and skilled probably players vs full team on his mmr and gear maybe.
It is like to que with triple que and to face 3 players solo qued.