As it stands, in higher ranges dota mmr has no cap. You keep winning, you keep getting more and more points.
But this is not what happens at lower levels which are capped at zero. It is very unfair for players in the lower brackets. The point of a good "ranking system" is for you to eventually reach a level in which you reach 50/50 chances of winning. That is, a level/range/bracket which is fair to you.
Dota's mmr is capped at 0 on the lowest point. I think this should not be the case.
What do you do with someone who is 0 MMR and has a 5% winrate? He is clearly less skilled than the people at that "level". The system is being unfair to him/her because he can never reach a 50% winrate. In addition, the ranking at 0 is—by definition—inaccurate.
Either you keep lowering the score of this person until he/she can find matches in which he/she can win 50/50—even if that means having a bot bracket—or you create more named ranges until you can properly describe the normal distribution of player skills.
As it is right now, the normal distribution breaks at Herald level; where there is a huge jump from Herald 2 to Herald 1. There are 221k Herald II players and 6k Herald I players.
Operating under the assumption that skill levels are normally distributed—a fair assumption—this leaves us with the impression that we could fit three more "ranges/ranks" below Herald I.
In addition to this, lower ranks suffer from smurfing and higher ranks from purchased accounts (giant-ing?), which introduce a lot of noise into the system. Like many of you know, a 6k mmr account sells at around 200 USD. How this affects the system altogether is beyond the scope of this post, but it should be kept in mind regardless.
Further complicating this, dota is a non-linear game where even one teammate screwing things up for everybody might drag down an entire team. So someone losing might not necessarily mean they are at bad at the game, just having the horrible luck of netting a bad team.
For instance, I do have a friend who is zero mmr. I also have friends in immortal, divine and ancient brackets. I've put this guy with those other guys, his winrate skyrockets and his KDA is similar to theirs.
Is this guy a bad player? Well, to me, he's not. To those guys, he ain't. I mean, he's not as good as they are. But he is able to function properly.
And that is the key here. At lower levels, even players that would be good in other brackets are not able to function properly. This is not saying that an immortal player in 0 mmr wouldn't be able to climb, it rather means that an above-average player stuck at a lower level has an incorrect/non-representative mmr.
And why are they stuck? Because you can't go lower than zero.
It is similar to "escape velocity", an immortal player has so much delta-v that they can escape to "high skill orbit" with some ease; where an above-average one can't generate enough impact to surpass the negative non-linear influences (gravity) that drag him down. Yet, if he was to start from a much higher position, his mmr would be more representative as a whole (faster).
For the aerospace people in the crowd, yes I know that one could escape Earth's gravity well by having an arbitrarily small amount of delta-v as long as it sustained—and you have the fuel for it. Applying this to dota, it would mean that even having a 51% winrate would eventually push some to the highest rank. Although in practice winrate is a function of rank; and that's where the analogy ends.
To further compound this lack of accuracy, the skill level of players varies wildly from hero to hero; where there's people that can be a 6k windranger and a 2k dawnbreaker.
However, instead of letting people play whatever hero they want; the system punishes free choice with the ban system.
What is wrong with people playing whatever hero they want? If you have a particular hero you want to enjoy on your free time, it is not fair to have you queue many many times until you get the hero you wanted. Moreso if you can execute that hero's meta much better than your other picks.
The folks at blizzard might've been stupid to neglect dota at the beginning, but Heroes of the Storm at least did that right, allowing you to join ranked queues by hero. You pick what you want to play, the system sorts out a party for you.
Compounding this problem even further, probably because of stagnation and time, the player base collectively plays better than before. An average 3k guy now has more game experience than one from three years ago. The gamers that keep playing the game have been doing so for years.
Meanwhile, the amount of players keeps going down and down.
If we, as a community, are going to get more and more people into the game—because that's good—we can't keep having the system as it is.
This needs a re-vamp.
Dota does not need to be as salty as it is already. Many of us have been playing this shit since it was a Warcraft Map, we all know it is extremely hostile to new players. It needn't be so. More now than ever, now that we are kind of going mainstream with the anime and all.
I'm not saying the current system does not work, it clearly does for the ranges in the percentiles where the negative effects of a horrible team are less pronounced. But for the lower brackets—where all the newbies are going to be—it frankly works like shit and everyone is super frustrated and many players just fucking leave before they can't even start.
I mean, who wouldn't? Chances are you're going to be yelled at, blamed for everything—even if it's not your fault—cursed to hell and whatnot, and have a negative reaction yourself from all the stress, whether it is you going ape-shit angry shouting, getting defeatist/depressed or outright uninstalling the game.
This is not the definition of a healthy game. Dota in this sense resembles more a toxic romantic relationship than anything else. You stay through all the shit that it gives you, until occasionally you get a great deal of satisfaction.
And when do you get that satisfaction? When the randomness of the game's matchmaking systems enables enough environment variables so that everything goes smoothly. It is almost an unintentional SKINNER BOX right there.
Some people realize this and leave the game forever. Do we want dota to die? I don't, but it will eventually happen at this rate.
If I run symbolic regression on SteamCharts' data of Dota's playerbase ever since its peak, all I get are functions that decay continuously until it disappears or it reaches a small asymptote.
Here are some of them counting from the month of the peak Feb-2016, where t is measured in months, t = 120 is Feb-2026.
Either we fix this game, or we let it die or its player-base slowly wither away or stop playing due to kids/old-age/cancer, whichever comes first.
Enough said, I'm going to go play some more dota.