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Registration for the virtual World Diplomacy Championship played on Backstabbr can be found here.

The Ghost Ratings are a group of true skill ratings developed on webDiplomacy by TheGhostmaker. The purpose of the Ghost Ratings is to approximate the skill level of webDiplomacy players relative to the rest of the players on the site. Since their development well over a decade ago, the Ghost Ratings have been tweaked and fully integrated into webDiplomacy. This page explains their implementation on webDiplomacy.

The Ghost Ratings are broken into seven categories: overall, gunboat, full press, live, 1v1 overall ELO, FvA ELO, and GvI ELO. The way of these categories is handled is described in detail below.

You can visit your profile
to see how you stack up. Just expand the Ghost Ratings categories in the middle section to see your
current rating and rank among all players. You can also see how you trend over time.

To see a more sophisticated breakdown of your GR, visit our
detailed GR breakdown page.

There are two formulas used to calculate your GR, one for 1v1 games and one for non-1v1 games. Both of
these formulas are based on the ELO rating system. However, they have different ways of computing the
score that you are expected to attain given the ratings of the competition you are playing against and
the actual score that you achieve in a given game.

In both 1v1 and non-1v1 games, your rating is calculated using the following general formula:

ratingAdjustment = x * (expectedScore - actualScore)

In the non-1v1 formula, "x" represents a scaling modifier that changes based on the settings of the game, derived by the following equation:

x = sumOfEachPlayersGR / (17.5 * pressWeightModifier * variantWeightModifier)

The press weight modifiers and variant weight modifiers for each category is listed with the category details.

We calculate your expected score in a non-1v1 game with the following equation:

expectedScore = yourGR / sumOfEachPlayersGR

If you draw in a draw-size scoring (DSS/WTA) game, we calculate your actual score with the following equation:

actualScore = 1 / numberOfPlayersInTheDraw

If you draw in a sum-of-squares scoring (SoS) game, we calculate your actual score with the following equation:

actualScore = yourSupplyCenters ^ 2 / allSupplyCenters ^ 2

Your actual score in a non-1v1 game is always 1 if you solo and 0 if you are defeated.

In a 1v1 formula, "x" is always 32. This value is constant, and therefore never changes.

We calculate your expected score in a 1v1 game with the following equation:

expectedScore = (10 ^ (yourGR / 400)) / ((10 ^ (yourGR / 400)) + (10 ^ (opponentGR / 400)))

Your actual score in a 1v1 game is 1 if you solo, 0.5 if you draw, and 0 if you are defeated.

In each category, each variants, press type, phase length, and scoring system that counts toward that category is
displayed. Additionally, the press or variant weight modifiers applicable to each category are listed with the
eligible variants and press types. These modifiers determine how large or small of an adjustment you will receive
to your rating when a game concludes. A small modifier means that you will receive a *larger* adjustment. To show
an example of this, let's use the modifier piece of non-1v1 formula, where "x" is a constant used to determine how large
or small of an adjustment you receive to the difference between your expected score and actual score:

x = sumOfEachPlayersGR / (17.5 * pressWeightModifier * variantWeightModifier)

A classic map, full press game in the Overall category has a variant modifier of 1 and a press type modifier of 1. Thus, the value for "x" is the sum of each player's GR divided by 17.5 (17.5 * 1 * 1). In an Ancient Meditteranean map, gunboat game in the Overall category, the variant modifier is 2 and the press type modifier is 4. Therefore, the value for "x" is the sum of each player's GR divided by 140 (17.5 * 2 * 4). If the sum of each player's GR in both of these games is 200, then "x" would be 11.43 in the classic, full press game, and 1.43 in the Ancient Meditteranean gunboat game. Plugging each of these values into the following formula, you can see that you will receive an adjustment 8 times larger for a classic full press game than an Ancient Mediterranean gunboat game.

ratingAdjustment = x * (expectedScore - actualScore)

Keep in mind that we treat 1v1 differently. The value of "x" above will always be 32 in 1v1, and thus there are no press type or variant modifiers in 1v1 games. With this in mind, click a category below to view which variants, press types, scoring systems, and phase lengths are factored into each category ranking, and the modifiers we use to derive your score.

- Classic (modifier: 1)
- Ancient Mediterranean (modifier: 2)
- World Diplomacy IX (modifier: 4)
- Fall of the American Empire (modifier: 4)
- Modern Diplomacy II (modifier: 4)
- Classic - Chaos (modifier: 8)

- Full Press (modifier: 1)
- Rulebook Press (modifier: 1)
- Public Press (modifier: 2)
- Gunboat (modifier: 4)

- Draw-size scoring
- Sum-of-squares scoring

- 1+ hour/phase
- 5 minute/phase - 30 minute/phase

- Classic (modifier: 1)
- Ancient Mediterranean (modifier: 2)
- World Diplomacy IX (modifier: 4)
- Fall of the American Empire (modifier: 4)
- Modern Diplomacy II (modifier: 4)
- Classic - Chaos (modifier: 8)

- Gunboat (modifier: 1)

- Draw-size scoring
- Sum-of-squares scoring

- 1+ hour/phase
- 5 minute/phase - 30 minute/phase

- Classic (modifier: 1)
- Ancient Mediterranean (modifier: 2)
- World Diplomacy IX (modifier: 4)
- Fall of the American Empire (modifier: 4)
- Modern Diplomacy II (modifier: 4)
- Classic - Chaos (modifier: 8)

- Full Press (modifier: 1)
- Rulebook Press (modifier: 1)
- Public Press (modifier: 2)
- Gunboat (modifier: 4)

- Draw-size scoring
- Sum-of-squares scoring

- 5 minute/phase - 30 minute/phase

- Classic (modifier: 1)

- Full Press (modifier: 1)
- Rulebook Press (modifier: 1)

- Draw-size scoring
- Sum-of-squares scoring

- 1+ hour/phase

- France vs Austria
- Germany vs Italy

- 1+ hour/phase
- 5 minute/phase - 30 minute/phase

- France vs Austria

- 1+ hour/phase
- 5 minute/phase - 30 minute/phase

- Germany vs Italy

- 1+ hour/phase
- 5 minute/phase - 30 minute/phase