To begin with, to reach this achivement, you must at least be able to get to 1800 rating.
So I'm going for Arena Master title. I've got 2,2k in all brackets.. but I'm still missing Hotter Streak. I counted and I've been
7 games in 4 times
8 games in 5 times
9 games in 2 times
I'm playing very weird setups (Mage/Boomkin in 2v2 for exampel) and alot counters us. It just seems like destiny didn't want me to get the achivement. But i tricked destiny by comming up with the following idea that i thougt just might work. I played down my team from 2235 to 1800. I asked a friend of mine to help me. I created an arena team on my priest. Lost 150 games on purpose (took ~1 hour). Just enter the arena, leave it, instantly sign again. Takes about 20 sec/loose. He's MMR hits the bottom and he joins the 1800 rated team on my mage. We make it to 10 wins in a row and even kept going a bit. We are on 34-0 at the moment, and still havnt lost one game so far ^^
Here we are at 985 mmr and i get my achivement (mmr will move from ~800-1000 by the time you win the 10 games)