Juan Xavier Larrea

So, you have been playing Gears of War 2 for a while now and you are wondering why you never rank up. You have a high win/lose ratio and have the most kills at the end of each match but still, you are stuck at some low rank. Needless to say, you feel frustrated.

I hear you! Stuck forever at rank 2, i decided to figure out how the hell the Gears of War 2 ranking system actually works. What i found was a little more complex (and way more interesting) than i expected. Actually, Gears of War 2 ranks the players according to the Microsoft TrueSkill ranking system used for almost all the multiplayer online games played over Xbox Live. Gears of War, Halo 3 and Call of Duty 4 are just a few examples of the many games that uses this ranking system.

The TrueSkill Ranking System

The TrueSkill ranking system is a skill based ranking system for Xbox Live developed at Microsoft Research. The purpose of a ranking system is to both identify and track the skills of gamers in a game (mode) in order to be able to match them into competitive matches. The TrueSkill system attempts to identify the correct ordering of n players in terms of 50 skill levels and only uses the final standings of all teams in a game in order to update the skill estimates (ranks) of all gamers playing in this game.

What you need to know

Without getting too technical, you can use the following tips to speed up your ranking in Gears of War 2. These arel also valid with any other game that uses the TrueSkill ranking system.

After a win, the TrueSkill system adjusts your individual skill ranking based upon the skill of all the players in the game.
• You don’t rank up or down based on your individual performance. If you have 30 kills at the end of a match your skill will change in the same proportion as that of another player who only have 1 kill.
• As stated above, individual statistics are worthless. It doesn’t matter how many kills, headshots, frags, Kill/Death ratio, etc. you earn at the end of the match. The only thing that matters to TrueSkill is whether your team won or lost. That’s it.
• The higher your opponent team average rank is, the faster you’ll be able to rank up. The lower your opponent team average rank is, the slower it will take you to rank up.
• It works both ways: if you lose a match against a team with a significant lower rank, the faster you will rank down. On the other hand, if you lose against a team with a significant higher rank, the less relevant the defeat will be and won’t impact as much in your own rank.
• A match of, say, Execution won 5-0 will be much less significant than winning it 5-4. The lesser the score difference, the faster you will rank up.
• The longer you have played, the longer it will take you to rank up. For example, it will take just a few matches you reach level 2. After that, it will take considerably longer to continue ranking up.
• You will rank up way faster playing a mode with more teams and less players per teams. In Gears of War 2, you will rank up 5 times faster playing Wingman than any other mode.
• If you don’t want to take the lose, you can quit early before the match finishes. You will NOT lose any points or rank down by quitting the game early.
• TrueSkill can’t identify cheaters.

The Technical Stuff

Your TrueSkill rank is calculated using the following equation:

Ranking = μ - (K * σ)

Rather than assuming a single fixed skill for each player, the system characterises its belief using a bell-curve belief distribution (also referred to as Gaussian) which is uniquely described by its mean μ and standard deviation σ (sigma). Finally, K is a constant assigned an arbitrary value by the developers of the game (usually 3).

The ranking system maintains a belief in every gamer’s skill using the μ (mean) as the average skill of the gamer and the σ (sigma) as the degree of uncertainty in the gamer’s skill. If the uncertainty is still high, the ranking system does not yet know exactly the skill of the gamer. In contrast, if the uncertainty is small, the ranking system has a strong belief that the skill of the gamer is close to the average skill.

On the curve above, a belief curve of the TrueSkill ranking system is drawn. For example, the green area is the belief of the TrueSkill ranking system that the gamer has a skill between level 15 and 20.

Ranking Up (Or Down)

In general, with x teams of y players in each team, the system needs x*y*log2(n)/log2(x!) many games per player until convergence, that is, for you to rank up (or down).

The following table gives an idea of the average number of games per gamer that the system ideally needs to identify the skill level:

Particularly, in Gears Of War 2, a player may need to play an average of 25 Elimination or Territories matches for the system to identify a significant change in the player’s skill. In the other hand, the player would only need an average of 5 Wingman matches

This rank calculator allows you to directly experience the TrueSkill ranking system as it is used in Xbox Live. It might give you a better understanding about what happens when you win or lose a game and how your TrueSkill rank is affected by the outcome.

Resources

Now you know what to expect from the Gears of War 2 ranking system. If you want more in depth and technical information, visit the TrueSKill Ranking System page at the Microsoft Research website. Even though I tried to summarize as much as possible the technical stuff, i highly recommend that you read the detailed description of the system and it’s FAQ. If you are in the mood for something heavier, go ahead and grab the technical report PDF.