BWFFL structure, schedule, and rankings explained

Background:
The BWFFL structure has the following features:

  • Three divisions (A, B, C)
  • Some interdivision play.
  • Unbalanced schedules for teams. This allows each team to play a different strength of schedule. Teams play opponents of similar ability, determined by the previous season’s standings.  This also prevents competitive mismatches between teams.
  • Power rankings for each team to help create division and league standings.  This is necessary because no two teams in any division play the same strength of schedule, and will not play a schedule of common opponents.

More about the rankings:
The rankings are determined by a formula called AQB, which is an ELO-based system, and which is used by several different professional sports leagues.  

The teams’ initial power rankings are determined by last year’s season records. 

Each week, a team’s power ranking will change.  The change in ranking is determined not only by whether a team won or lost, but by the strength of their opponent. A win will improve a team’s power ranking.  In addition, beating a higher ranked opponent improves a team power ranking more than does beating a lower-ranked opponent. Similarly, a loss will drop a team’s power ranking.  A loss to a higher-ranked team, however, will not drop a team’s ranking as much as a loss to a lower-ranked opponent would.  This helps assure that teams are assessed not only how many teams they beat, but on the quality of the teams they beat.

The formula is created to provide a fair, accurate assessment of a team over time.  For this reason, a win or loss may help a team to move up or down slightly in the standings.  However, no single win or loss can drastically move a team up or down in the standings.  In addition, a team who has a great (or horrible) season can move slightly up or down in the end of season standings.  However, it is mathematically impossible for a team to rise or drop dramatically in the standings based on the results of just one season. In short, no team, no matter how successful  or horrible their season, will as a consequence find themselves competing two divisions higher or lower the next season, or playing a strength of schedule that puts them in a level of competition that is at odds with their true ability.  The true measure of a team’s strength, ability, and standing is determined over several seasons, not just one abnormally strong or weak performance.

Power rankings are updated weekly. Power rankings are determined by both the outcome of the game (win/loss) and the strength of the opponent. In this system, a team's initial (pre-season) power ranking is used for the first game of the season to calculate how much its opponent will gain (in a win) or lose (in a loss) towards its new standing for week 1. For each consecutive week of the season, the previous week's power rankings are used to calculate the ranking differential between teams for that week. Therefore, teams' rankings evolve over the season based on both win/loss records and the strength of their opponents as borne out over the season.

Power rankings do NOT factor in margin of victory; therefore, no team benefits from running up the score in any game.

Playoffs
The three different divisions will each have their own playoffs.  The division in which a team begins the season is the same division it will play in for playoffs.  There is no movement between divisions within the season, (even though it is mathematically possible for a team in a lower division to have a higher power ranking than a team in a higher division by the end of the season).
Playoff seeding in each division is determined by power rankings, not by win-loss records. The top 4 teams in each division will advance to the playoffs.


Playoff results will NOT affect teams’ end of season power ranking numbers.

End of season assessment
At the end of the regular season, team reps will meet to discuss and evaluate the merits and shortcomings of the league structure.

If it chooses, the league can then choose to use the end of season power rankings as a way to determine standings and division placement for the next season. 

General Explanation for Pre-Season Ranking Adjustment:

The rankings work by accounting for strength of schedule in each of our wins and losses so that we can all play a competitive schedule and yet still compare ourselves as a league, despite our different schedules. The rankings are meant to reflect each teams overall strength based on their performance over time. However, a team's end of season ranking one year isn't necessarily a perfect measure of the strength of that team going into the next season. Things change, new personnel are added, growth occurs, losses occur, etc. Also, over the years, with no adjustments, the teams on the top and bottom of a league can drift further apart. Therefore, a lot of ranking systems make an adjustment to pre-season rankings to pull all the rankings a little bit back towards the league average so that the next season's performance carries a little more weight relative to the historical data embedded in the unadjusted ranking. As decided by the league reps from each team, BWFFL will be doing this each year starting in 2016.

Exact calculation: The difference between each team's ranking and the league average ranking is calculated. About half of the teams have a ranking above the average and half below. 15% of that difference is removed for each team, thus bringing each ranking closer to the overall league average and bringing all teams somewhat closer together.  A team whose ranking happens to be exactly the same as the average would not change, whereas teams at the very top and bottom of the league would change more.