It looks like Halo 5 is upping its competitive features, and that means taking a few cues from Riot and Blizzard when it comes to multiplayer matchmaking and rank. But one unique feature will act like a safety net for your rank, just in case you go on a bit of a losing streak.
Halo Waypoint detailed the process in a blog post. After ten placement matches, the game will estimate where you should be in the grand scheme of Halo skill, and drop you there to climb the rest of the ladder by yourself.
One might assume it'll err on the side of dropping you lower than you should be, instead of higher. Not only is that a typical move to give you a feeling of progression, but the game won't actually drop you in rank. The six tiers within a rank are one thing, but you won't actually be demoted for losing:
As you win, you will progress through the 6 tiers of your rank. If you are skilled enough to continue winning at tier 6, you will advance to the next rank (yay!). Losing games will cause your progress within a rank to decrease, but you will never drop down a whole rank from losing. For example, if you spend all month working your way into Silver, losing won’t drop you back to Bronze.
Of course, the ranks and tiers could all just be a bit of smoke and mirrors to make you feel good, while your actual matchmaking rating will be hidden -- until you reach Onyx rank, that is, when it will pull aside the curtain and reveal the hidden wizard. At that stage, you can see your matchmaking rating, and when you're in the top 200 of that category, you'll rise to Champion rank.
It's a bit like how Hearthstone acknowledges the highest rank you achieved in that particular season. Except, Halo will always be acknowledging it. Because that'll still be your rank.
There are some other interesting decisions as well, such as the choice to not allow drop-ins or drop-outs in certain modes. Check out the full post here.