Match Play Ratings

Match Play Ratings (MPR) is a pinball rating system based on head-to-head results. It is a free service, and the match data comes from a variety of sources.

Individual match results are used to calculate a player's rating whenever they participate in a tournament. Match Play Ratings does not concern itself with results from best game tournaments, pingolf tournaments, selfie leagues or any other indirect play tournament formats. Only tournament formats where players compete head-to-head or in groups directly against each other are eligible for inclusion.

Eligible tournament formats

In Match Play Events, the following tournament formats can be submitted to Match Play Ratings:

• Head-to-head match play
• Group match play
• Round robin / double round robin
• Flip frenzy
• Knockout
• Group knockout
• Single elimination bracket
• Group elimination bracket
• Pingolf bracket
• Ladder elimination bracket

In addition, the following software can submit results to Match Play Ratings:

• Drains Tournament Manager
• Challonge
• Brackelope
• Seattle Monday Night Pinball

Submitting results

Whenever you close an eligible tournament on Match Play, you'll be asked to confirm that the tournament was a pinball tournament and that you wish to submit the results to Match Play Ratings.

If your tournament was not organized using Match Play Events, you must submit the result using the Match Play Ratings website. Switch to the Ext. Events tab and click the Submit event button. There you can paste in a link to your tournament.

In addition to tournaments, challenge matches are also included in Match Play Ratings. All challenge matches are automatically included and no explicit submission of results is required.

In all cases, your tournament will not be processed until seven days after the tournament. For example, tournament results for September 14th are calculated on September 21st. This delay gives tournament organizers time to verify and submit results.

Tournaments will be placed into a rating period. Each rating period starts at 00:00:00 and ends at 23:59:59 in the UTC timezone. The time a tournament is concluded determines to which rating period the tournament belongs.

Understanding rating numbers

Match Play Ratings are calculated using the Glicko algorithm. This means a player's strength is made up of two numbers: their rating and their rating deviation (RD). A player's rating is a best guess of the player's strength while the rating deviation describes how confident we are that the rating is accurate.

A player's strength is most accurately described as an interval rather than a single number. The interval is the player's rating plus/minus twice their RD. For example, a player with a rating of 1500 and an RD of 30 would be written as 1500 ±60. You'll also see a graphic representation of this interval in use.

In some cases, a player's strength must be represented as a single number, such as when determining rating restrictions for different divisions. In those cases, the lower bound should be used. The lower bound is the rating minus twice the RD. If a player has a rating of 1500 and an RD of 30, the lower bound is 1500-(30*2) = 1440.

Finally, a ranking number is calculated by comparing the lower bound of all players in the system.

There are two main differences between Match Play Ratings and the IFPA WPPR system. First, MPR only concerns itself with direct play between players while the IFPA WPPR system estimates individual rankings based on indirect play (like comparing two players in a best game tournament who never played each other directly). Secondly, the IFPA WPPR system is purely additive, meaning your ranking will never decrease as a result of participating in a tournament. Under Match Play Ratings, a player will see their rating decrease if they perform worse than expected in any tournament. Both are perfectly valid ways to estimate the strength of a player, but one method may be more accurate than the other depending on your use case or the make-up of your local player base.

Glicko constants used

The following configuration is used for the Glicko implementation:

Provisional rating

1500

Max. RD

125

Min. RD

15

System constant c

3.7775

Rating period

One day

Initial rating period

January 1, 2016