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Memoir '44 » Memoir '44 Online - English » Explanation of the ELO ranking
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Yann
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Explanation of the ELO ranking Wed, 16 June 2010 16:16
Recently, it was asked how the ranking would work in Memoir '44 Online, especially in regards to the fact that scenarios are often unbalanced. Who would be willing to play the Allies at Omaha beach, with only 22% of chance to win?...

We came up with a simple solution to this issue.

As usual, the ranking system is based on the classic ELO system that we have been using for years and which works nicely.

If you are not familiar with the ELO system, this is the system used in international chess ranking.
Basically, ELO computes an amount of points that depends on the previous ranking score of each player, and on who won the game. The winner's score in increased by this amount, and the loser's score is decreased by the same amount.
If the winner was already much better ranked than the loser, then he wins only a few points, because the outcome of the game is considered normal. But if he loses, his score is reduced by much more points, as the system is trying to move the winner up the ladder.
In an ideal world, the system converges and stabilizes if everyone plays at his strength and wins (or loses) as expected. Of course, this is never completely true - which makes the whole thing interesting, but let's no digress here Smile

To keep the explanation simple, let's consider two players of equal strength and ranking - so we have a fixed and identical amount of points at stake. How do we handle the Omaha Beach case?

It's very simple: the amount of points given to the winner is compensated by his probability of winning.

Example: say we have 32 points at stake. If the Axis win at Omaha, they will get 32*22% = 7 pts. If the Allies win, they get 32*78% = 25 pts (almost 4 times more!).

In other words, if you have less chance to win, it's compensated by the potential reward.

The ice on the cake: we also take into account the performance of each player, compared to the average score for each side. This is the purpose of the "thumb up" and "thumb down" icons in your game history, and why we show the average values in the AAR screen.
On Omaha Beach, the average score for the Germans is 5.5, and 3.1 for the Allies. The idea is that you get 10% of bonus (or malus) for each medal above (or below) the average. So say you lose 5-6 playing the Allies: you opponent get a 6-5.5=0.5=5% bonus and you get a 5-3.1=1.9=19% bonus, which makes a 14% difference in your favor. As a result, the amount of points he will earn will be reduced by 14%. He won, but not well enough. Twisted Evil

It does not change dramatically the result in the end, but it is still a good incentive to keep playing even if you are in a hopeless situation, and try to sell your life as dearly as possible! It should help resolving the issue of impolite players who quit games that they think they won't win. It also keeps an interest for both parties up to the very end of the game.

Conclusion: if you really want to make lots of points, play against someone much better ranked than you, on the Allies side at Omaha Beach, and win 6-0! Piece of cake Smile

Yann

Note: keep in mind that the ELO ranking is something completely different from the Officer promotions system - which I promise I will explain in a future memo.

[Updated on: Wed, 16 June 2010 16:19]

      

SubjectPosterDate
  Explanation of the ELO ranking  YannWed, 16 June 2010 16:16
  Re:Explanation of the ELO ranking BrummbarWed, 16 June 2010 16:49
  Re:Explanation of the ELO ranking YannWed, 16 June 2010 16:53
  Re:Explanation of the ELO ranking BrummbarWed, 16 June 2010 17:28
  Re:Explanation of the ELO ranking yangtzeWed, 16 June 2010 19:33
  Re:Explanation of the ELO ranking YannThu, 17 June 2010 07:50
  Re:Explanation of the ELO ranking henryblakeThu, 01 July 2010 11:16
  Re:Explanation of the ELO ranking LotusArdentThu, 17 June 2010 10:22
  Re:Explanation of the ELO ranking YannThu, 17 June 2010 13:51
  Re:Explanation of the ELO ranking bdgzaThu, 17 June 2010 14:26
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