by Dubuque Independent Football League, 2015-10-05T22:13:46-07:00October 05 2015, at 10:13 PM PDT
The final 2015 playoff brackets have been finalized and are available online. The brackets include seed (rank), team match-ups for both playoff games and consolation games, game dates and times, and game locations. Use the links below to download the bracket documents.
Three criteria were used to determine each team’s seed, which is the number next to each team name on the brackets, and which determines the team match-ups.
- Team’s winning percentage
- Team’s RPI
- Team’s head-to-head results with other teams having same winning percentage
First the teams are sorted based on winning percentage. Then, within each group having the same winning percentage, there is a secondary sort based on RPI.
Head-to-head factor is only taken into account if two teams have the same winning percentage and the team with the higher RPI lost during the regular season to the team with the lower RPI. When this happens, an adjustment is made so that the team who won the head-to-head match-up is ranked higher. This only happened in one case this year. Prior to taking into account head-to-head play, WD Red (D2) had a 7 seed and Maquoketa Cardinals (D2) had an 8 seed, but since Maquoketa Cardinals (D2) beat WD Red (D2) during the regular season, the seeds were adjusted so that WD Red (D2) had an 8 seed and Maquoketa Cardinals (D2) had a 7 seed.
What is RPI?
RPI, or Rating Percentage Index, is a popular metric used to rank teams based on strength of schedule and strength of opponents’ schedules. It is sometimes preferred as a tie-breaker compared to other metrics like points scored, points allowed, and difference between points scored and allowed, because those other metrics result in undesirable play during the regular season (running up the score). Also, in a small league with a small number of games played and in which teams do not get an opportunity to play every other team at least once, points-based metrics do not adequately reflect teams’ strength of schedule, strength of opponents’ schedules, etc. This is where RPI shines. In the case of DIFL playoffs, it is only used as a secondary sort to break ties when multiple teams have the same winning percentage. Head-to-head results can override RPI in cases when two teams have the same winning percentage and one team has a higher RPI even though that team lost to the other team with a lower RPI.
How is RPI calculated?
RPI = (0.25 x WP) + (0.50 x OWP) + (0.25 x OOWP)
WP = Winning Percentage
OWP = Opponents’ Winning Percentage (average the WPs of all the team’s opponents)
OOWP = Opponents’ Opponents’ Winning Percentage (average the OWPs of all the team’s opponents)
Obviously this is a complicated calculation considering that each team played six opponents, and each of those opponents played six opponents. This website is supposed to automatically calculate RPI, and it appeared to be doing so throughout the season. But once the regular season was completed, and RPI actually became relevant, the DIFL board realized that the website was not calculating RPI correctly—not even close. In fact, in some cases, the incorrect RPI values were creating results that were the opposite of what should have been the results. This malfunction was confirmed by TeamPages technical support staff. Since TeamPages does not know how long it will take them to fix their automatic RPI calculator, we “turned it off” and replaced it with our own manual calculations.
Questions? Comments? Concerns?
Send email to email@example.com and, if you are challenging the seeds determined by the DIFL board of directors, be sure to include your calculations.