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  • Subject: In depth explanation of the Halo 3 skill ranking system.
Subject: In depth explanation of the Halo 3 skill ranking system.
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I won like 70 games in a row and only ranked up to highest skill 33. send me a pm if you want me to know cuz im going to bed now. night guys ~

  • 09.14.2008 3:56 AM PDT

Posted by: WE ALREADY LOST
Since it takes around 50 to 100 games for Bungie to get enough information on your account to accurately detect skill change, does that mean it's easier to increase your skill level with a new account rather than an older account, or quite the opposite?

Thanks for answering my previous question.
Well, here is the issue. A new account OR the first time you play in a playlist, has no "history". This basically means your sigma is high. So, when your sigma is high you can gain skill quicker if you win. An account with a lot games in a playlist, will take more wins on average to gain a skill level.

Usually, if you start a new account, you will land within 2 or 3 skill levels of your original account. The difference is, you get to that skill level much faster since all your "learning" was done on your original account.

  • 09.14.2008 10:05 AM PDT

Posted by: l KxS Lyle l
Let me rephrase my question:

If you play with someone that has negative exp, will that help you increase in rank faster or do you have to have the negative exp?

Simple yes or no will suffice. =]
Simply having a neg EXP won't help you gain skill. It is a lot more complicated than that. If you have an established account and play with someone with a neg EXP, it won't help at all - this would be a NO.

If you have a neg EXP, it won't help you gain skill and quicker - this would be a NO.

  • 09.14.2008 10:07 AM PDT

"In the streets we only had 1 rule, no groin hits... home for dinner!"

willkommen mein bekanntschaften

my youtube channel... check it out!

thanks man, wicked post. extremely informative ... but i still think i'm gettin ripped off in terms of the actual matchmaking. i am currently a grade 2 colonel, and i fight nothing but generals and brigs. that is my main concern about the matchmaking

  • 09.15.2008 5:50 PM PDT

Posted by: Jay120171
Posted by: damn Juggernaut
thank you. It make a little more sense. Something I still don't get is if what you said was true, then the equation is not right.

Ranking = mu - (K * Sigma)

As Sigma gets smaller ranking does too.

Try this:
mu=25
k=3
sigma = 8

25 - (3 * 8) = 1 your skill level during your first game

Play a game and win then you get
mu=26
k=3
sigma=7

26 - (3 * 7) = 5 your new skill level

Sigma has decreased after the win but you get MU for the win as well and your new skill level becomes 5 instead of the initial 1. Now these equations are over-simplified but it shows how it works without getting in to decimals.



That just confirms my previous idea. The higher the sigma is the lower your ranking will be, but if you are winning the mu increase should outweigh the drop in sigma.

I guess what the O.P. is trying to say is the higher ones sigma (more unpredictable) the faster they will level up or level down.

On my second account I won 60 consecutive games in TS and only leveled to 18. I'm not saying that to complain. I'm here to point out a flaw. I know I'm not the only one with this problem. Microsoft believes they don't have to make adjustments because it was a scientific study. I think they did a poor job collecting feedback. They made a system and did not respond to feedback.

  • 09.15.2008 7:29 PM PDT

thank you for this

  • 09.15.2008 8:48 PM PDT

Posted by: damn Juggernaut
On my second account I won 60 consecutive games in TS and only leveled to 18. I'm not saying that to complain. I'm here to point out a flaw. I know I'm not the only one with this problem. Microsoft believes they don't have to make adjustments because it was a scientific study. I think they did a poor job collecting feedback. They made a system and did not respond to feedback.
I am guessing your were playing with the same teammates for all of those wins. This is usually the only explanation for this slow of a progression. If you and your friends all start new accounts and only play together, you will level very slowly and usually get stuck around 15. I am also guessing that one or more of you played a few games with randoms but not enough to prevent this slow progression. Without seeing your account, I can't say for sure but this is usually the cause.

This is an issue that we've seen since launch. What or if Bungie has done anything to try an minimize this effect is unknown but they are aware of it. MS designed the system (TrueSkill) but that system is also configurable and Bungie has configured it for use with Halo 3. Bungie can make adjustments to it if they deem it necessary.

  • 09.16.2008 6:47 AM PDT
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why does that happen when you play games with say 3 or more people you won't go up at the same rate as you would if you played by yourself

even if you win against higher ranked levels than you and say you were on a brand new account

doesn't make sense if you are winning games consecutively against higher ranks you should level up but instead it keeps you from leveling up just because you are playing with friends

let me ask a question do you think that the ranking system should partially, completely or not at all depend on in game performances.


does any one have any solid information on this

personally i think it should but should still take into consideration the ranks of the opposing team

either way it seems bungie or microsof t should make some changes to the system

and if i interpreted the explanation right isn't it kind of odd that after so many games and wins that your ability to level up decreases

[Edited on 09.16.2008 7:50 PM PDT]

  • 09.16.2008 7:40 PM PDT

Honestly, this must be a joke. Child, listen, stop trying to defend yourself because clearly you are incapable of it. The only idiot in this thread is yourself, and trust me, it is obvious. So, how about you do as I asked earlier and log off, mommy and daddy wouldn't want you staying up this late.
-- Direct Control, BAMF

Posted by: Jay120171
Posted by: damn Juggernaut
On my second account I won 60 consecutive games in TS and only leveled to 18. I'm not saying that to complain. I'm here to point out a flaw. I know I'm not the only one with this problem. Microsoft believes they don't have to make adjustments because it was a scientific study. I think they did a poor job collecting feedback. They made a system and did not respond to feedback.
I am guessing your were playing with the same teammates for all of those wins. This is usually the only explanation for this slow of a progression. If you and your friends all start new accounts and only play together, you will level very slowly and usually get stuck around 15. I am also guessing that one or more of you played a few games with randoms but not enough to prevent this slow progression. Without seeing your account, I can't say for sure but this is usually the cause.

This is an issue that we've seen since launch. What or if Bungie has done anything to try an minimize this effect is unknown but they are aware of it. MS designed the system (TrueSkill) but that system is also configurable and Bungie has configured it for use with Halo 3. Bungie can make adjustments to it if they deem it necessary.

I watched my brother make a new account and play by himself, he ranked up really fast up to 10 and it didn't change for the next 20 or so wins. I think that if you win so many times in a row by so much you might not level up fast at all because the system could think you are a second account, I told him to lose a few games and he started to level up again when he won.

  • 09.16.2008 7:49 PM PDT
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The real gankfest was when we had the Honor system but no BGs. That was a terrible time. I was in the high 40s on a PvP server, within range of the 60s. It was supremely unfun. It's why I have a character on a PvE server now.
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Promote your website

  • 09.20.2008 3:35 AM PDT
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Kool post.

  • 09.20.2008 4:09 AM PDT
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Nice.

  • 09.28.2008 3:10 PM PDT

Back.. and to the left.
Back.. and to the left.
Back.. and to the left.
Back.. and to the left.
Back.. and to the left.
Back.. and to the left.
Back.. and to the left.

Hmm, i think that having social ratings might defeat the point of it being social. It does make sense but in a team game, what if your team carries you to being a high rating then you go in the playlist alone, get paired and suck?

[Edited on 09.28.2008 6:07 PM PDT]

  • 09.28.2008 5:48 PM PDT
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This is good stuff, a lot of Q's answered.

  • 10.01.2008 6:39 PM PDT
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One of the fundamental parts in the Halo 3 ranking system is the relativeness of your performances. In team games you will rank up very slowly because the system takes all kinds of factors into account which will waylay your progress to higher skill.
When you play lone wolves and keep winning you will rank up fast until a certain point and then slow down and maybe not rank up anymore. To reach the highest skill 50 you will need to improve your game ( the system detects this the best in Lone Wolves) and consistantly beat higher ranked players and earn more medals.
Personally Im an achievement junkie who likes to earn everything but with this system I will probably get to HS rating 40 and then stop improving. ( note that I havent really played Lone Wolves to improve my skill yet, only to earn achievements - got em all now) So after 8 lost games on high ground and Isolation trying to get Mongoose Mowdown and some bad results in Spartan Laser maps I got the achievements and was happy. I played a few games of LW after that and ranked up 2 to 3 skill per match again because of my losing streak.

Im gonna try and get my highest skill to a more representative height later on, but I just want to point out that this system WORKS. When I play a general and he owns me I know Im just not cut out to earn 50 highest skill. This is the way Bungie made it. They play the game themselves and they know its the best way to give players their Rank. In COD4 everyone reaches highest level so lets be very happy that when we become - Major, Colonel, Brigadier, Commander, or General we actually ARE that rank and well get promoted when we improve our win/loss, hit/miss, medal count in ranked and we actually earned it.

Quote piggyback's guide to Halo3: "your highest skill rating is a crude hard fact that you are better than your friends, the opposite - alas - is also true"

Have fun, and dont be mad if you dont rank up fast enough (which is fastest in Lone Wolves).

  • 10.02.2008 2:52 AM PDT

There are 10 types of people in this world. Those who understand binary and those who don't!

Sorry, haven't read all the posts, but thanks to the OP, that was very informative.

I hope I can explain it to my team-mates, next time they gripe about me increasing skill while they don't.

  • 10.02.2008 3:30 AM PDT

~Infamous.

Thank you. that's all.

  • 10.02.2008 4:40 AM PDT

"You know the music. Time to dance"
"and laugh, and laugh, and laugh."
[Edited on 12.25.2009 12:52 AM PST]

Posted by: El Kafungus
I am NOT an employee of Bungie nor one of Microsoft, and my views and opinions do not necessarily reflect those of either of the aforementioned entities.
Also, thanks for sticking this Bungie, I hope it is useful.


There is one caveat to consider before we get under weigh. Bungie is not likely, nor or ever, to release the true inner workings of the Halo 3 ranking system, but as it is based somewhat on the Microsoft Trueskill system, this is a fair approximation of the way skill ranking works in Halo 3.

What is the Trueskill system?
The Trueskill system is a player skill rating system for Xbox Live. Halo 3 uses a version of the Trueskill system in order to make the matches fairly even.



How Does Trueskill Work?
Trueskill assigns skills on a normal distribution (bell curve, Gaussian). The Trueskill system has two main variables to consider. They are your player skill level (Mu) and your uncertainty factor (Sigma).

Mu is an approximation of your skill level based upon past performance. Win games to raise Mu, and lose games to lower Mu.

Sigma is the numerical representation of the range in which your true skill could lie. Play really consistently, and you have a low Sigma. Play streakily, and you have a higher Sigma.

After a win, the Trueskill system adjusts your skill ranking based upon the Mu and Sigma of all the players in the game. We'll go deeper into how much it is adjusted later.

Trueskill systems use a conservative ranking Ranking = mu - (K * Sigma) so your skill is likely to be higher than the actual number represented in your Halo 3 highest skill level. K is a constant assigned an arbitrary value by the developers of the game.



Why don't I level up after winning X games in a row? / Why does my friend go up three levels a game and I don't?
Mu increases after a win. Always. The increase is proportional to the winner's Sigma and the Mu difference between the winner and the loser. So, if your Sigma is high, you will proceed faster through the ranking system (in BOTH directions). If your Sigma is low, you will both gain and lose rank more slowly.



So, I want a high Sigma value?
While it sounds as though a high Sigma value is desirable, it CAN be a double edged sword. A high Sigma can mean you increase by one level for every win. It also means you decrease by one level for every loss. In addition, a high Sigma means that your skill ranking will be significantly lower than your actual skill owing to the conservative nature of the Ranking = mu - (K * Sigma) ranking equation.

Also, Sigma value starts out VERY high. So, if this is your friend's first time in a particular ranked hopper, and he wins consistently, his rank will rise meteorically due to his high Sigma.



Myth Busting
Trueskill DOES NOT take into evaluation performances inside the game. The ONLY statistics that Trueskill takes from a game are the Mu and Sigma values of all the players, and how you placed.

This means that out of all of these statistics:
Getting the MVP
Having a High K/D ratio
Getting the most medals
Skill levels of those you killed / killed you
Weapons you used
Headshots
Captures, detonations, stops, ousts, etc.

NONE of them matter when calculating the Mu increase/decrease. Any link between any of these and the skill ratings are purely correlative and not causative.

For example. When I play Team Slayer with my buddies on my alternate gamertag, much of the time I end up carrying the team. I created this tag to play with my buddies, and as such, have only ever played on that party with that tag. I ranked up to the level of my friends within 20 or so games, while it had taken them 50 to 100 games to reach their level. My friends thought that it was because of my frequent MVP status and my high K/D ratio that I leveled up so fast.

Wrong. I leveled up fast because A) I initially had a very high Sigma, making my Mu more variable after each win, B) Starting out at a 1 and playing people in the mid teens gave me a considerable boost every time I won, and C) We won more frequently than they had in the past.



Summation
If you're worried that you're not getting your fair shake in the ranking system, look at the last 50 games that you've played in that hopper. (If you haven't played 50 games, play more. The system needs more data.)

Take your win/loss average. If it's 65% or above, and you've been in that playlist for a while, you've probably increased in level 2 or more times over the last 50 games (or you will in the next 20 or so). Otherwise you are going to be hovering around the same level or dropping in rank.



Addendum, Opinion, and Technical Notes
In strict Trueskill systems, Sigma only decreases. I believe the "momentum" system in Halo 3 means that Sigma can be increased through consistent winning or losing. This is total conjecture, but I think that Sigma in Halo 3 matchmaking hoppers is proportional to the absolute value of the win/loss ratio of your last X number of games. The formula probably looks a little like: Sigma = C ( | wins - losses | ) where C is an arbitrary constant. This would explain why when some people go on a win streak with two or more different parties, their skill goes up faster than their teammates' skill.

I also believe that the system is weighted so that the peak of the normal distribution is around level 20, not level 25. That means it will take more wins to level through 1-25 than it will 25-50. Which makes a bit of sense, if you don't want the highest levels too terribly crowded.

The higher the Sigma of your opponents, the less Mu you gain from beating them.

Predictable outcomes (e.g. win against a lower ranked opponent) are treated as statistically less significant. Upsets are given more weight. So, winning against lower ranked opponents doesn't do much for your Mu rating. Neither does losing against higher ranked ones. But beat a team that's 6 or more ranks above you and at least someone on your team will rank up.

Trueskill ratings have no discernable correlation from hopper to hopper. When you play on a hopper you've never played on before, you are starting with a fresh Mu and a high Sigma.

Team Mu and Team Sigma are the summation of the Mu and Sigma values of all the players on the team. When calculating the skill of an opponent in a team game, the system uses the Team Mu and Team Sigma values in calculation wherever rational.

*Removed equations for space. They can be found in the link below.*

The rest of the equations and a less Halo 3 centric analysis of the Trueskill system can be found here.

_________________________________________________________
Important additions, Appendices, and Member Questions Answered
_________________________________________________________

In-depth response to a post LoveNub made later in this thread. Should clear things up for some.

More data analyzed, and a request for help with research

Kudos to Jay120171 for finding the post detailing the Mixed Party Bug in matchmaking.

"Why do I win 10 games and not level up, then delevel when I lose 2? Help!"

There are several possible explanations for this. The easiest one, and the one that fits the Trueskill system EXACTLY as explained by Microsoft, is that losing against a team that is X (I believe 6 or more, but experimentation is needed to determine the true value) skill points below you can cause you to lose as much as 5 times the Mu value that winning against even level teams gains you. Of course, winning against a team that has X more skill levels than you can net you as much as 5 times the Mu gain. The reverse is true as well. Winning against a weak team can count as little as 1/5th of an even skill win.

Second, and this is enlightened conjecture, your Sigma value was low at the beginning of your streak, and since your win streak is raising it, the conservative ranking system (Remember, Rank = Mu MINUS (K times Sigma)) is kicking in to reduce your apparent skill level. Your real Mu is higher, but your higher Sigma is having a negative impact.

mo0vaf00 writes: (edited to clarify intent)
So is there some kind of value that requires you to be inconsistent to rank up? If I win 1 game going even and win the next going +10 do I have more of a chance of ranking up than just winning 2 games getting the same score?


This conclusion is popping up fairly frequently. The answer is no. The system does not look at "In Match" statistics. At all. These stats are all included in a list above. The game only looks at your wins and your losses, and the strength of the opponents you play against.

Also, the system does not "reward" you for having a high Sigma value. There is ONE positive associated with high Sigma, and there are TWO negatives.
Positive: Your level can move up faster through winning.
Negative: Your level can move down faster through losing.
Negative: The conservative ranking system ranks you lower when your Sigma is higher.


good explanation

PS: 74 page!!!

  • 10.02.2008 12:26 PM PDT

Ich bin Reptar!

Wort Wort Wort!

  • 10.03.2008 5:26 PM PDT

What is sigma? I was told it was used for the ranking system, what is it and how do I gain it or lose it? Please explain :P

  • 10.04.2008 11:43 AM PDT

Feel free to msg me over B.net or XBL if you wan't to talk halo or any other game.
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I would like a bungie moderator to put the final word in on how it works I think we should know once and for all personaly

but good job

  • 10.06.2008 9:34 AM PDT

cheers mate, it was long winded but i got the jist of it, its like reputation high u get more points lower you get less points. SO you need to play more games if you are not getting any xp

  • 10.06.2008 12:24 PM PDT
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Posted by: WhatHitu
I would like a bungie moderator to put the final word in on how it works I think we should know once and for all personaly

but good job


Don't need to. There are links to Microsoft literature within that clearly affirm 99% of what is said within the thread.

  • 10.06.2008 2:11 PM PDT
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Awesome post

  • 10.06.2008 5:46 PM PDT
Subject: Perhaps a tweak is in order...

So, after analyzing this explanation (which is great), there are two factors that strike me as being a weakness to the existing TrueSkill method and could potentially be easily modified.

Weakness 1: Quitters
Let's say I play with randoms in a ranked Team Slayer match. If two of my team members quit, they will individually lose an EXP point. They get punished, but what about me and my remaining teammate; we are now significantly disadvantaged. Could we perhaps introduce a "relevance" factor that could essentially negate (or extremely devalue) the importance of this game?

Weakness 2: The LVP (Least Valuable Player)
I think many will sympathize with this one. How many times are you playing a 4-player Team Slayer match and you end the game with a double-digit positive K/D spread, only to lose the game thanks to a teammate's beautiful -15 performance? I'm certainly willing to grant exemptions for the individual with double-digit assist numbers, but for one individual's poor performance to drag down the whole team seems rather illegitimate. This is where I think a mathematical analysis of the internal K/D spread would be beneficial.

John +7
Frank +2
Teddy 0
Mike -10

This is an example of a team that lost a match 49-50. Although, clearly, Mike appears to be the party to blame. Or vice versa...

John +11
Frank +6
Teddy -1
Mike -11

This is a team that won the match 50-45. Perhaps I'm putting too much emphasis on the K/D spread as a metric, but wouldn't it make sense to distribute the victory points (or blame) as deserved:

In the loss: Mike loses EXP, the rest are exempt from loss.
In the win: John receives approximately 70% of the credit, Frank receives 30% of the credit. Teddy and Mike receive no credit.

--------

Certainly, I understand if Bungie felt this destroys the intent of team play, so, alternatively, there might be better solution. Create a ratio of the number of games won to the number of games lost with a positive kill spread and incorporate in the uncertainty (sigma). This would go a long way to solve a number of issues -- the player who seems to unfortunately always get matched with poorly skilled or quitting teammates would no longer be punished for the factors that he could not control.

And, finally, a general question -- any chance that we could see our sigma and mu values?

  • 10.10.2008 12:10 PM PDT