IQA Update

IQA Standings Update

by IQA Staff | November 7, 2013

Editor's Note: The IQA would like to thank Martin Pyne, of the gameplay department, for his efforts creating the new IQA ranking system.

A simplified standings algorithm has been created for the upcoming ranking system. With the new standings, we hope to see more intuitive results. Players should have an easier time understanding the standings as well.

The new standings system has four primary parts: SWIM, strength of schedule, adjusted win percentage and penalties. For a full technical explanation of these elements, visit Quidditch Reference.

The first portion, SWIM, stands for “Snitch When It Matters.” SWIM is basically adjusted quaffle point differential with diminishing returns on snitches catches that did not affect the game. Here is the breakdown of how SWIM is determined:

1. Quaffle point differential is determined. The quaffle point differential is the point differential when the game ends, minus the points scored by catching the decisive snitch.

2. Quaffle point differential is adjusted for blowouts. Whenever the quaffle point differential is over 80, the value of additional points is decreased.

3. The snitch is factored in. If the snitch points decided the game, the full value of the snitch is added in. If it was a suicide catch, the snitch points are not included. If the winning team caught the snitch, but was already winning by a lot, the snitch points are added in at a partially depreciated value.

The value you get after these three steps is the SWIM score for the winning team. The losing team’s SWIM is the negative value of the winning team’s SWIM.

Second, SWIM is multiplied by strength of schedule. Strength of schedule is 2/3 of your opponents’ winning percentage and 1/3 your opponents’ opponents’ winning percentage. This equation is similar to Rating Percentage Index (RPI), a statistic used in college basketball rankings.

Third, the resulting value is multiplied by adjusted win percentage. The equation for this is (win percentage + one)/two. This slightly waters down the impact of win percentage; without doing so, teams that lost a lot of games would be overly penalized even if they played a very tough schedule.

Finally, penalties are applied in certain circumstances. The final value is reduced for certain reasons:

1. Five-game minimum - At least five games must be played by a team in a single season. The fewer games played, the harsher the penalty.

2. Three different opponents - A team must play at least three unique opponents in a single season. The penalty assessed is inversely correlated with the amount of unique opponents faced (less people = harsher penalty).

3. Two-event minimum - A team may not play all of its required games for the season in one single tournament. All games played per tournament count as one event. Games outside of tournaments are one event each.

After this modification has been made, all of the teams are compared and the standings are compiled.

For those eagerly anticipating the release of the official IQA standings, a rough version of the statistics can be found at Quidditch Reference. These rankings only include games submitted to the Gameplay Department, therefore, many official games this season are missing from the configuration, particularly, records from the Southwest region.