Best way to fix matchmaking on Normals.

Simply reset every year like ranked. Completely refreshed MMR.

However the MMR will look at your RANKED MMR and base you on players on that skill level if you win a lot the MMR will verify and go upwards to the next rank. To see if you do any better (Say your with bronze. You win too much. You'll go to a more silver player base instead.)

Also a good way would also be to SHOW what your MMR NUMBERS are. So people can complain about those numbers and their ACTUAL Rank in Ranked ;)