WARNING: Do note that I did this out of sheer boredom so there could be some things I'm wrong on. I'm no statistics expert and most of the information I'm getting is just first-hand and from the internet anyway. Feel free to correct me in the comments on some points I made.

Every time I hear the term "Elo" in games, it's always referring to the rating system and more often than not the game isn't using Elo, and the same goes for Valorant. So, as any other bored person would do, I did some small research on rating systems and compared them to how it works in Valorant.

First off, you have two separate ratings: your matchmaking rating (MMR) and your rank rating (RR officially, but some call it LP or League Points). Your MMR comes first and is what often determines who you queue with and, to a much lesser degree, calculates your skill in a hidden algorithm. Then, after you play a couple of games, you've unlocked Ranked and with that the MMR will calculate where you are in skill and match you up accordingly with whatever rank your next team is. After this, you play about three games and then the system, working its magic with your new -- currently hidden -- RR, will give you the estimated best rank for you. The rating systems will now introduce a new equation (i don't know the official name for it, if it was ever given one) that will act as "your average score" which indicates what RR your given after every victory. If you perform within your average, you'll get an average score, usually represented by +22 or +26. If you perform above your average, however, you will be awarded accordingly and given more points, somewhere in the +30 range.

All of this is similar to, or may as well be, the Glicko-2 rating system and here's why I think so.Glicko-2, as some or many of you may know, is a heavily-modified Elo system, adding in a system known as the rating volatility σ (Sigma). This new system, like your "average score," calculates your performance, rewarding you depending on how well you do. But that's not the only similarity. There's also rating and rating deviation (RD), which measures your points within a rank and the accuracy of said rank respectively. Same goes for how MMR and RR work hand-in-hand to determine rank and matchmaking queues.

So yeah. TL;DR, even if it doesn't seem like it, Valorant seems to use Glicko-2; if not, a slightly modified version of it.

One day I'll probably go into what the old rating system probably was, but only time (and level of boredom) will tell.