Ladder League Math

Team rankings and each week’s opponents in a ladder league are determined by all of the teams’ results from week to week. Basically, teams move up the ladder when they win a match and move down when they lose a match. The number of places a team moves up or down on the ladder is explained below.

How far up or down a team moves depends on factors such as the game scores of the match, if the match went two games or three, and importantly, how the teams above and below scored as well.

A team that wins or loses a match 11-0, 11-0 moves up or down more than a team that wins or loses a match 11-9, 9-11, 11-9. Teams can win or lose a match and not move at all on the ladder depending on the match scores of the other teams above and below them.

The exact movement of any team on the ladder is determined by mathematical formulas using the following method:

Game Score Differentials: The differential between your points scored and your opponent’s points is calculated for each game in a match. If you win or lose by 2 points, your rating improves or decreases by 0.35 ladder positions. If you win or lose by 11 points, rating improves or decreases by 2.05 ladder positions. For every point differential between 2 points and 11 points, your position increases or decreases by 0.1888 ladder positions. The total of the game score differentials for each game in a match is then averaged to get the total movement score.

Game Wins: The winning team increases by 0.95 positions and the losing team decreases by 0.95 ladder positions. The net up/down movement of winning or losing a match is heavily weighted towards the game scores.

Ladder Movement: The Game Score Differential number is added to the Game Wins number to come up with the total ladder movement value for each team after all matches are played each week. That number is added or subtracted to each team’s current ladder position to determine each team’s new ladder position and the teams are then re-ranked for the following week’s matches. Ladder rankings each week are done entirely using these algorithms – there is no manual intervention.

Adjusting for Duplicate Opponents: Any team that has a matchup adjusted to avoid playing duplicate opponents still retains its actual ladder position even if it is not playing in that position on the ladder for any given match. For example, a team in ladder position #4 that should be playing the team in ladder position #3 may be moved down to the next ladder matchup to play the team in ladder position #5 or ladder position #6 to avoid a duplicate matchup. The placement for the next match is then based on the math calculations as if the team had played in ladder position #4.