The Elo rating system is a method for calculating the relative skill levels of players or teams. It is named after its creator Arpad Elo, a Hungarian-American physics professor. With Dawn of War II: Retribution, the old TrueSkill (TS) rating system used in Dawn of War II and Dawn of War II: Chaos Rising was abandoned in favor of the Elo rating system.
Arguably the most significant change in Dawn of War II: Retribution is the new matchmaking system. The previous two titles used the TrueSkill system, which had some weaknesses when it came to RTS matchmaking. One of these was that there wasn't enough granularity in the ranking. With only 50 TS ranks, it was hard to separate players, and especially hard to rank them on a leaderboard. With Retribution Relic implemented a modified Elo system, used in competitive chess and many RTS games.
In the Retribution Elo system, players start at 0 points and play a series of matches in a placement phase. During the placement phase a player's skill rating will increase to a number around the 1500 mark. After that players will gain or lose points depending on whether they win or lose, and the degree to which depends on the strength of their opponent. That is the basic system but there are a couple of twists.
The first twist is a rest system. Relic looked at what Blizzard did with Battle.net and were impressed the implementation of this system, as it has several benefits. The rest system works in the following way: From the release of the game players accrue points on a daily basis. When a player wins a match and their rest pool is larger than 0, additional points are added to the points they would normally get for a win. For example, if you win and receive 12 points, the rest system would add an additional 12 points to your score. The reasoning behind this is that instead of punishing inactive players with decay, a rest system gives incentive for active players to continue to play on a regular basis to use their rest. Another advantage is an inactive player using the rest bonus can quickly rise up to their proper skill rating, without spending too much time beating up on players less skilled than him.
The second twist is a hidden streak modifier. When players go on hot and cold streaks, the system will modify their score in the background and match them to more appropriate players. When you go on win streaks, you will continue to match higher and higher rated players. This will allow more skilled players to rise faster. Alternatively, when you go on cold streaks, you will match lower rated opponents. These additions to the traditional Elo system should keep players matched against other players around their proper skill level.
Leaderboards and Steam player statsEdit
Naturally because the matchmaking has changed, so has the leaderboard. It looks roughly the same as previous Dawn of War II leaderboards, but will rank players based on their displayed skill rating. This is typically a three to four digit number and is based on the player's previous matches. During the placement phase, a player's score will typically only increase even with a loss, but once a player has reached the end of their placement, their score will increase with a win and decrease with a loss.
There is also a Steam player stats page so that players can check their stats even when outside of the game. It shows basic stats such as which campaigns you have beaten and your win/loss percentages with each race in multiplayer.
Apart from having an in-game Elo rating, Dawn of War II: Retribution also keeps an Elo rating in the player's Steam profile. This Elo rating has neither the rest bonus nor the win-streaks, and actually gives a more accurate grasp of a player's skill than the in-game rating. This unmodified rating is also used for matching opponents – i.e., players are matched according to their "Steam Elo" and not to their "in-game Elo" ratings. More on this can be found in the appropriate www.gamereplays.org page.
- Elo rating system on Wikipedia