Premier Ratings (TCG)

Premier Ratings are a points system used in the Pokémon Trading Card Game, introduced by Play! Pokémon (formerly known as Pokémon Organized Play) and designed to reward players who consistently perform well at Premier Events over the course of the tournament season with the opportunity to participate in the World Championships at the season climax.

POP tracks these ratings throughout the season via the information sent to them by Tournament Organizers and League Leaders. Players can use the ratings to measure their success at tournaments, their improvements as a player, and to compare their play during the current tournament season against their highest ratings of previous seasons.

Tracking Ratings and Rankings

All players that participate in Premier Events obtain a Premier Rating. These ratings can be accessed through their My Pokémon account, and if they so wish, they can choose to participate in POP Player Rankings to see how they compare to other players. Each player starts with a Premier Rating of 1600.00.

Each time players win a match at sanctioned tournaments, their Rating goes up. Each time they lose such a match, their Rating goes down. Rankings are determined by comparing Ratings against other players in a specific area.

Calculating Premier Ratings

After the results of matches or tournaments have been uploaded to POP, the new Ratings are calculated through the official website using two formulae; Win Expectancy (which is based on comparing two opposing players' Ratings), and the number points won or lost (which is known as the "Stake"), which is based on the Win Expectancy. This method is based on the Elo rating system.

Win Expectancy

First, the Win Expectancy is calculated for the two players using the following formula:

File:WinExpectancyEquation.png

Where

• E is the Win Expectancy
• P_A is the current Premier Rating of Player A
• P_B is the current Premier Rating of Player B

For example, if both players' Ratings are the same, the Win Expectancy is 50%. Players with high ratings are 'expected' to beat players with lower ratings more often than they lose to those players, so the Win Expectancy goes up if a player is rated higher than their opponent, and down if they are rated lower.

Stake

Second, the amount of points is calculated for each win/loss. This amount is based on the Win Expectancy, the Outcome of the match, and what is called the "K factor." The K factor represents the competition level of the event, with larger numbers reflecting higher levels of competition. The Outcome of the match is 1 for a win and 0 for a loss. The winner of the match gains points equal to the stake and the loser loses the same number of points.

The Stake is calculated using the following formula:

File:StakeEquation.png

Where

• S is the Stake
• K is the K factor of the event
• O is the Outcome
• E is the Win Expectancy

The Stake is smaller if the higher rated player wins the match – they are expected to win. If the underdog wins the match, the Stake is larger to reward the achievement.

Here are a few sample results of the formulae above, using a K factor of 32.

On average, a 20 point difference in Ratings is equivalent to 1 point difference in the Stake, which is larger if the higher rated player loses than it is if that player wins.

There are circumstances where players may receive no points for playing matches. The most frequent is in the Age Modified format, where players can battle each other across the age divisions. By scrutinizing seasons over the years, POP came to the conclusion that players who play matches against opponents in an age group above their own lose that match, meaning even highly rated Junior players are at a severe Ratings risk and disadvantage when playing against Senior or Masters players. To help maintain the integrity of the Ratings system, POP ruled that cross-age division matches don't count toward Ratings. In addition to cross-age division matches, players who receive a bye or forced loss (due to late arrival to an event) do not gain or lose rating points for those rounds, as no match was played.

The Ratings are reset after the World Championships have come to an end, ready for the next tournament season. This not only ensures that the tournament environment is more vibrant and alive by giving everyone an equal starting point for the year, it also gives morale to less experienced players, as they are essentially starting on an equal footing with other players.

K factors

Each Premier Event has a different K factor. They indicate the maximum number of Rating points at Stake for each match. These values were updated with the beginning of the 2008-2009 season, now making State/Province/Territory and Regional Championships as equally important as National Championships.

Though still referred to as "Premier Events," Prerelease Tournaments are not incorporated in the Premier Rating system.