Ranked, How Does it Work?

I was wondering how ranked really works, under the hood, and I couldn't find a good explanation in any one place. What follows is my best understanding of how this whole shenanigan hangs together. At the most basic level, yes, winning games makes you climb. But it's a fair bit more nuanced than that. I post the following for other ranked newbies, to help demystify the process. DISCLAIMER: I'm, like, low Silver (currently bronze III, thanks placements!). So I probably don't know what I'm talking about.

When you queue up for any game of League of Legends, in any queue, matchmaking has one simple goal: to match you up as fairly as possible. LoL uses a system wherein every player is assigned a Match Making Rating, or MMR (this rating is kept seperate between queues, so your ranked MMR is nothing like your aram MMR, for instance). This is, hopefully, an estimate of how good of a player you are - higher MMRs are better. So League simply has to match you up against other people around the same MMR[1].

What this means is, EVERY SINGLE GAME YOU PLAY IS DESIGNED TO OFFER YOU AS CLOSE TO 50% ODDS OF WINNING AS POSSIBLE. This helps ensure that games are as intersting as possible. All other things being equal, League will never deliberately match you up against people you're supposed to stomp hard, or lose hard to. This will be important later, keep it in mind.

Now, MMR works essentially the same way as the ELO rating system in chess[2]. The simple breakdown goes like this: For every game you win, your MMR goes up. For every game you lose, your MMR goes down. If you win against someone with a higher MMR than you, your MMR goes up MORE. Conversely, if you lose against someone with a higher MMR, your MMR goes down less. The same is true against opponents with low MMRS: your wins count for less, and your losses are bigger. In theory, this shouldn't matter much to league, because the pool of players is so large that your opponents' MMR shouldn't matter much.[3] Simply put, by winning games, your MMR will go up.

It's worth mentioning your MMR is officially hidden. There are sites out there (like op.gg) that can help you estimate it, though.

Here, we finally get into how ranked is different from the other leagues. Every player in ranked is sorted, via placements[4], into divisions and tiers, for instance Bronze III, or Plat V. These divisions, as you might expect, are designed to contain players with around the same MMR. As you play ranked games, in addition to the hidden MMR stat, you gain and lose League Points (LP). You can see this in the client, on the "League" tab of your profile.

Once you hit 100 LP, you have a chance to go up a division. As soon you hit 100, your next 3 (5 if you're in division I) games are considered "Promos". If you can win a majority of these games (2/3, or 3/5), you are promoted to the next division up (Bronze III -> Bronze II, Silver I -> Gold V, etc) and set to 0 LP. If you reach 0 LP, you run the risk of dropping to a lower division, or even tier, if you continue to lose games. You won't drop immediately, to prevent people who just hit the division from dropping right out. It's unclear exactly how many games you have to lose to drop.

Some explanations stop here. But this is where things get interesting. As I previously stated, in every queue, league's matchmaking system will try to match you up against 50/50 odds. This is true in ranked games as well - if your MMR is way higher than other people in your division, league will PLACE YOU AGAINST HIGHER DIVISION OPPONENTS. On its own, this would be crazy unfair - if league is trying to make your win rate 50/50, how can you ever get LP?

As it turns out, LoL gives you MORE LP for a win, and LESS LP for a loss, if your MMR is much higher than your division's average. For instance, you may gain 30 for a win, but only lose 10 for a loss. This is completely independent of the MMR difference between you and your opponent. In fact, this entire system exists purely to help shove you up (or down, if your MMR is lower, the reverse effects are true) to the next division/tier.

What most people don't get is, in theory, your win rate really shouldn't ever be that high. Most people's intuitive thinking is, eventually they will be better than other people in their tier, and go on some crazy winning streak and earn that 100 LP in one go. The truth is, though, that you have to increase your MMR first, by grinding out games and getting better. Then the LP system will naturally cause you to rise out of your league.

This is why checking your MMR is so important: if your MMR is currently tanked, you will, on average, lose LP NO MATTER WHAT YOU TRY. The system IS rigged against you. The solution is to play more games, have a slightly higher win rate, and gain MMR over time. The point is, tracking your progress by LP is a fool's game. Your LP gain/loss rates are merely a symptom of your MMR, you really can't (or shouldn't be able to, at least), affect them, if everything is going according to plan.

Well, there you go. That's ranked, as I understand it. Hopefully someone finds some of this useful. If I'm wrong about some of this, I'd love to know.

P.S. By the way, this helps explain how smurfing works. People with very high MMRs make fresh accounts, tank their placements intentionally, and get dropped into low divisions. By winning an enormous percentage of their games, their MMRs shoot through the roof. This in turn causes their LP rates to skyrocket. High LP gains + high win percent makes them climb exponentially faster.

[1] I have never found a definitive answer for how this works from a team perspective. I think it attempts to match each team's average MMR for all 5 players, with some extra math in there to make things more complicated. I've heard rumors that premades get 'bumped up' in MMR, that MMR is somehow weighted and not a simple average, and all kinds of stuff. It remains a mystery to me.

[2] https://en.wikipedia.org/wiki/Elo_rating_system

[3] How this is impacted by you playing against a premade with someone +300 MMR from you and someone -300 MMR is unclear, for the same reasons as note 1. I have no idea how league's team nature affects this.

[4] I don't even attempt to understand how placements work. I know your previous season MMR plays a big factor, and that most people tend to place lower than they ended last season.