For those of you who aren't familiar with the terms MMR and MM, they basically help creating a fair environment for players to compete. MMR (matchmaking rating) is a numerical value that measures your skill level, which will then be used by the MM (matchmaking) system to find others who have a similar or identical value as yours.

The MMR and MM system are visually different in many popular competitive video games, but they all work similarly:

1) All players start at the same MMR =/= 0.
2) They will have to go through a placement process to determine where they belong in the skill ladder. The MMR will increase for a win and decrease for a loss.
3) After the process, players will gain a new MMR which will be used to match with others who have a similar or identical one.
4) This process is repeated when the devs reset the MMR or Visual Rating (which I will explain later).

The most important thing to make this work is to have a changable MMR, as in, one that can increase or decrease.

There is a hidden MMR in ESO, but what numerical value ZOS is using to calculate a player's MMR is still unknown. However, we can safely assume that the current MMR is based off of total medals earned, because the more you play, the longer the queues, regardless of whether you won or lost. Since you don't lose medals, this assumption is valid.

With that in mind, I think the current BG MM system is poorly implemented because of these reasons:

1) It does not promote team-based competitiveness, since players can simply ignore objectives and go for kills to rack up medals for a higher MMR.
2) It does not provide an incentive to self-improve, because gaining medals is easy and since players can only gain medals, not lose them, they can simply play more to achieve a high MMR.
3) It does not promote a fair and healthy PvP environment, because a weak and strong player can be matched against each other if they have similar MMR. Since MMR does not decrease, the weaker player will be stuck at that rating fighting much better opponents. It's not fair for the weaker player, nor is it fun for the stronger one.

In my opinion, there are two approaches to this issue:

1) Keep using medals as the MMR, but players can only earn them if they win the game. If they lose, they will gain zero medals from that bg match, while also losing X amount from their total medal count. For example, if I gained 1k medals in a BG match and lost the round, i would not get that 1k, but also lose X amount from my total medals earned. This will solve all three problems listed above, because players will now have to focus on winning the game as a team if they want to climb the ranks, self-improve if they want to climb, and face opponents similar to their skill level now that medals can be lost or gained.

2) Use an entirely new numerical value as the MMR, while keeping medals as achievements. The new numerical value will increase for a win and decrease for a loss. This will be the best approach in my opinion, because it will still let players who play BG for achievements get them.

More things can be added to encourage BG competitiveness with this separate MMR, such as adding a Visual Rating (which is unlocked for reaching a certain MMR, can be lost or regained, but does not affect the real MMR and is purely for players' bragging rights. I.e "Skull Crusher" at 1.5k MMR, "God Slayer" at 3k MMR", etc.), rewards that get better with each MMR rank up, or a better leaderboard.

I understand that ESO is an MMO, but it has the potential to have a competitive PvP environment. WoW has done it, albeit with far more players. Still, I believe BG can become something great.