Halo Reach Arena Rating

Arena Rating for Mathletes
rating = loss_penalty * (1000 + (2000/pi * atan( raw_rating * game_normalization ))) raw_rating = (kills + sa*assists) - (sd*deaths + sb*betrayals) game_normalization = players_per_team / score_to_win

The lowest (worst) theoretically possible Game Rating is 0, and the highest is 2000. The highest possible Rating in Slayer Arena in the Beta is 1844.

values
sa = 1.0 sd = 1/2 sb = 1

beta values
sa = 1.0 # assists are as good as kills sd = 1/3 sb = 1

score ranges is 0 ~ 2000, where 1000 is baseline

Divisions

 * Onyx – Only the best of the best will thrive in this Division. Access is extremely limited.


 * Gold – Great players who demonstrate excellent aim and well executed teamwork.


 * Silver – Like most players, your aim is true, but you're not quite ready to take on pro players.


 * Bronze – You are not yet instilling fear in your opponents, but you are no easy mark.


 * Iron – You're just getting warmed up. Keep honing your skills and you're bound to improve.

Player population is not divided equally between each Division. For example, only five percent of all players will qualify for the Onyx Division.

beta
These are the Divisions in the Beta...

5 = Onyx (best) 4 = Gold 3 = Silver 2 = Bronze 1 = Steel (worst)

So if I keep getting a high Game Rating, I'm going to be put in Onyx, right?
Not necessarily. All that matters is how your Game Rating compares to everyone else's Game Rating in a single game. It doesn't matter whether you have the highest Game Rating with a score of 1800 or the highest Game Rating with a score of 1500. Both will have the same impact on your rank.

If you have a Game Rating of 1750, and someone else has a Game Rating of 1751, your rank is going to be negatively impacted from having a lower Game Rating than that person above you.

There's likely to be a correlation between constantly getting high Game Ratings and getting a high Division, though.

assists
The number of kills you assisted a teammate with. In Reach, an assist is defined as "doing 40% or more of the damage required to kill a target that dies to other causes before a shield recharge can occur."

loss_penalty
If your team loses, this is a penalty applied to your rating.

But wait, you protest: "Isn't the Arena about individual performance?" It is, so our goal is that this penalty is as small as possible while still accomplishing two goals:


 * 1) Assuming equal performance, a player on the winning team should place ahead of his counterpart on the losing team.
 * 2) Playing for a personal best rating should require winning. No hanging your team out to dry to shoot for a high score.

For the Public Belta, this number is 0.96. In other words, if you lose, we shave a mere 4% off of your rating. We will be continuing to adjust this number, and we might even shift the place where this penalty is applied.

This number is 0.96 for the release version as well.


 * Taken from http://www.bungie.net/News/content.aspx?type=topnews&link=BWU_043010