Definitions

There are a lot of words below, and before we dig in let me define a couple of important terms so less people get lost.



MMR

Stands for Matchmaking Rating. It’s a term I coined long ago at a different studio when we first introduced the idea of having a separate, more accurate, backend rating that persisted season to season.



Ideally, it is the best prediction of how well a player will perform in their very next match so that we can matchmake them correctly, regardless of how we eventually rank them.

In Halo 5, we have also use it for driving our Ranking system, which will be explained more under “CSR” below.



Also, in Halo 5, we just replaced the original MMR system with TrueSkill 2, which is record-breakingly better at predicting player performance than the old system was.

This is a raw number we use on the backend to drive both matchmaking and Ranking systems.



We keep it separate from the number we Rank you on in Halo 5 under the philosophy that MMR is our best “prediction” of your performance, whereas “Rank” should be what actually happened, and a measure of if you can prove you deserve your MMR.



The older MMR system was less accurate, and so we required a lot of matches to get your “Rank” to what your MMR predicted it should be. We did this by artificially initializing ranks below the MMR after placement.



CSR

Stands for Competitive Skill Rating. This is the visible measure you receive that indicates your current skill-level. You see this as Bronze, Silver, Gold Platinum, Diamond, and Onyx, with Champ just being the top Onyx players. It is initialized after 10 placement matches using the MMR you had at the end of those placement matches. It then goes up when you win and down when you lose, based on the difficulty of each match.



In the past, we also have subtracted 100 (and way in the past 200) off your MMR when we initialize it as a CSR in order to encourage players to “prove” they deserve their true CSR.



CSR initialization used to come from our older MMR system, but with the TrueSkill 2 update, now comes from an MMR created by TrueSkill 2 instead. This MMR is much more accurate and needs very few games to assess a player’s skill. Therefore, it is less important to enforce “proving” you deserve the MMR, but probably still psychologically useful.



In addition, CSR updates after a match have always been computed by comparing your current CSR to the MMR (NOT CSR) of everyone else in the match. This ensures that CSR converges on your actual performance, and isn’t stagnated by 50/50, matchmaking. With the new update, the CSR vs. MMR computations are more accurate than ever. Players still must win to go up, and will still go down when they lose, but the amounts will better reflect each player’s actual abilities than in the past.



Ranking System Updated

As we announced and as many of you have seen, we have rolled out TrueSkill 2 into Ranked play. It is now being used for both matchmaking and Ranking. It directly decides placement, and then indirectly biases the CSR updating from match to match.



This means Placements may end up quite different than in the past because it’s a new system with new opinions about how good each of you are. It’s also a more correct system, so even if you get a different Rank than you expected, that Rank is based on a system that is better at predicting winners. See more below.



Also, while TrueSkill2 by far prefers players who win, it also incorporates kill and death information, as well as quitting behavior. This means even if you lose, it’s possible that your MMR will go up. So, you can lose even most of your placement matches and still get a good Rank if you had much worse teammates and still played well. Once you are placed, you can’t gain CSR for losing, but you can have your MMR go up. If this happens, you will get that back over time as CSR when you next start winning. It will also mean you will lose less CSR on your losses because if your MMR is higher, the CSR update assumes you were more responsible for the win, and less for the loss. Likewise, MMR can go down if you perform poorly compared to the rest of the players on your team, or in your party, resulting in eventual CSR losses.



This also means that it will be hard to get carried or boosted to a higher Rank. TrueSkill 2 will likely give your better teammates the better Rank, while giving you one closer to what your actual performance was. While this may hurt some egos, it will overall create a more fair experience for everyone. It means when you aren’t playing with your better friends, you don’t find yourself in overly difficult matches, and you also don’t misrepresent yourself to those players who play against you.





Usual -100 and 1700 Restrictions Removed for this Season

Normally, we place players 100 CSR back from where their MMR would place them after placement. We also usually restrict the max possible CSR to 1700 to force Champs to grind and earn their final ranks. All of this is artificial however, and often results in CSR underestimating a player’s actual skill.



This season, with the rollout of TrueSkill 2, we have removed this restriction. This means a Champ-level player can place directly into, e.g. 2400 right out of placement.



This helps us to stress test the Ranks a lot faster than waiting for players to grind it out, especially given not all players will take the time to do that.



We have heard feedback that this makes it feel like a lot of these Ranks haven’t been earned. We do empathize with this feedback because it aligns with our original reasons for enforcing the grind in the first place. We will highly likely reenable the restrictions in the next season.



That said, the current Ranks are still appropriate. TrueSkill 2 does not need 10 matches to assess a player’s abilities, unlike the older system. This means we don’t really need the artificial grind as much anymore. Part of the reason we had it was because we knew the older system couldn’t be precise enough in only 10 games, and the grind would ensure only the best really got there.



TrueSkill 2 doesn’t have this drawback. Every one of these players have turned in worthy performances over the course of their placement matches, and any one of them could be, e.g., Champ players.



But, again, we agree that it should feel more earned from a design point of view and will likely reinstate the previous restrictions.





I was Onyx for the last three systems, but now I’m Diamond!

The short answer is, the new system is right and the old one was wrong all along. The new system doesn’t know at all what the old system said about you in previous seasons. It looks at the same exact data (all of your previous matches) and makes its own judgement about your skill.



Some of you will find yourselves with higher ranks than before, and some lower. The new ranks are more accurate though, see below for more on that.