I constantly see discussion related to this topic, mostly from players who feel that matchmaker is rigged by using MMR. Or from players who simply want only SR and not hidden rank. So I would like to post my opinions, predictiond and positives and negatives to conclude if removing MMR would be better for game.
Current overwatch competitive system is using MMR(not visible rank) which I imagine as number just like SR is to avoid confusion with +3-3 stuff. Matchmaker is creating games with both teams having same average MMR if thats possible. Basicly giving 50% chance to win for both teams. Sometimes matchmaker will create games with lower chance when player pool is too small and waiting would be too long. At worst is your chance to win 40%. Games with possibly less chance are not created. By my experience are games like this usualy created only at the bottom or top ranks where player base is small. Odd play hours are often reason too, again small player base is reason.
I think that MMR is more precise representation of player skill than SR because it is directly affected by player action. SR is a lot more affected by actions of other players and other different events as leaving match or by using voice chat to either help win or lose if people are raging or tilting in voice. Player can play well, keep his MMR higher than SR but lose match simply because he will tilt someone for example and player will throw.
So what is better? Match players by using MMR or SR? I will try to present few points or things which are/would be affected by it.
*INTELLIGIBILITY/SIMPLICITY BY USING ONLY SR:
One rank, simple representation of place in ladder system. Result of own skill, team loss/win and communication. It is possible that winning or losing game is affecting MMR in current system, but probably only very little, because if you climb SR, but play bad, MMR will start pushing SR down by giving less SR for win and taking more for losing. It is not fully explained what is affecting the hidden rank so using only SR would probably make things more simple and players could actualy brainstorm what is affecting SR gain/loss alot better. Question is, if thats a good thing, because it could be abused.
PLACEMENT
I am not exactly sure how would switching to only SR affect initial placement. I dont think it would radicaly affect it tho, because initial placement and after placement bonus is highly win/loss based anyway and not so heavily skill based.
SEASONAL PLACEMENT
Not many people even know why we have seasonal placement right know. Or what is purpose of it. It is kind of double edged sword right now. Basicly seasonal placement is there to correct your SR and bring it closer to your MMR. Were you unlucky and had some throwers or leavers but still played very good? Seasonal placement and MMR is your friend and will try to place your lowered SR closer to your higher MMR. I see seasonal placement as recalibration to make your MMR and SR equal. But problem is that you can win games by having excellent communication and shotcall, but not having so impressive stats. In that case will current placement system and MMR still push you lower. Thats why having MMR and seasonal placement can be both good and bad. There is no point to have seasonal placement if MMR will be removed and only SR will be used.
SMURFING
I think it would be a lot easy to derank account because it would not matter if you played like god few games and then throw few games to stay lower. Overwatch is trying to push SR towards MMR and it is affecting smurfs too. If they want to have fun, they have to throw double amount of games to keep low elo than play games where they can dominate. If not more than double. It is actualy pretty hard to keep low rank and dominate in games in current system because of MMR. Without it? I could dominate 1 match gain 50 sr and completely throw next and lose 50. So deranking and actualy staying at lower elo would be a lot more easy, because it is more easy to affect SR in one match than affect MMR where you need more games to have impact on it. Not only that. Since there is not more stable hidden rank, smurf on your team would affect negatively your stats. Why? Because system without MMR would have to be based a lot more on stats from every individual game. So everyone would be gaining less when smurf would practicaly steal stats. What if you will have thrower or enemy team will have smurf?Tough, because you will be rolled and lose a lot of SR because again same thing, system without MMR would have to rely on stats from individual games a lot more.
LEAVERS
Leaving in current SR/MMR system have direct impact on your SR, but is not affecting MMR. I tested this myself few times during placement games and by leaving 4 games in row. I was gaining more sr per win after as game tried to push my sr back closer to MMR. Same can be actualy used in initial first placement season, where it is better to leave bad game instead of staying and lowering MMR with bad stats. Leaving = no stats so your MMR doesnt go down or up. But without it and with only SR? Left games would have much bigger impact as they would lower own rank significantly more, because there is no MMR to push you back higher.
BOOSTED PLAYER
I believe they would drop back to where they belong a lot faster without MMR, because as I explained above, system without MMR would have to be heavily stat based every individual game.
CLIMBING
Ok so how would climbing work without MMR? I think with only SR would be climbing a lot more chaotic and own SR more unstable without MMR which is working as anchor not so easily changed as SR. Every negative thing as smurfs, leaver or throwers would be more impactfull resulting in higher SR loss because your SR has not connection to more stable MMR. And I dont think games would be more balanced either, not at all If anything it would be worse because players would be moving on the ladder having certain SR but having often different skill. But just as boosters, people with significantly higher skill who try to win would most likely climb faster to where they belong. Normal players who are not smurfs or boosted, would probably experience a lot bigger SR spikes, having episodes of dropping massive amount of SR or gaining it in shorter period of times, more than now without having anchor in MMR.
So yeah thats all, you can challenge my opninins or change my mind, or just share what you think about removing MMR from matchmaking.