Development of a generalized formula for ranking teams could include 19 criteria. The formula consists of margin of victory performance against opponents of varying strength, strength of schedule, ratings percentage index of opponents' win-loss records, game site (home or away), and quality of wins based on the ranking of teams (compute, polls, RPI). These ratings can produce results for multiple teams in multiple sports at different levels.

The general formula is made up of 19 components, where any or all may be incorporated depending on the coefficient or weight factor selected for each (a coefficient of 0.0 eliminates that component):

PR =


As an example, if a rating was based on 50% strength of schedule, 25% won-loss percentage, and 25% polls, the the formula would be as follows:

PR = 0.50 * SOS(5) + 0.25 * WLPct(8) + 0.25 * Poll(19)

The numbers in parentheses indicates which specific component (see below) is used, as there are multiple criteria or methods for several components.

(1) Margin of Victory (Local)

Margin of victory calculations base ratings on the scores of actual games, the strength of the opponent (power ratings), and the home field advantage. Ideally, if you subtract the ratings of two teams, the results will indicate the winner and margin of victory if the two teams met on a neutral field. Only local games (i.e., games played among teams in a common state, division or league) count. A more detailed explanation can be found at margin of victory. This component is also referred to as "Reg In."

(2) Margin of Victory (External)

Once the margin of victory power ratings are established, all external (non-local) games (such as games played out of state) are computed. If a team exceeds the predicted results based on power ratings, it is awarded points and vice versa. So, if the power ratings of two teams are compared and team A is expected to beat team B by 3 goals and wins by 6 goals, then team A is awarded a 3-goal bonus. A more detailed explanation can be found at margin of victory. This component is also referred to as "Reg Out."

(3) Ten-Goal Limit (TGL)

In order to discourage running up the score, points awarded to a team defeating another team by more than 10 goals in the MOV calculations are subtracted under the TGL correction component. Likewise, if a team was expected to win by 20 goals but kept the margin of victory to only 10 goals, TGL points are awarded to that team in an amount equal to the MOV loss that the team received for not performing to the predicted 20-goal margin. Any gain an underdog team receives when the victory is held to 10 goals instead of the predicted 20 goal will lose TGL points equal to the unexpected gain from the closer than anticipated game score. A more detailed explanation can be found at 10-goal limit.

(4) Correction Factor

Bonus points are awarded to victorious teams for overperforming. Likewise, points are deducted from a losing team which underperforms. The number of points added or deducted is proportional to the difference between predicted margin of victory and actual margin of victory. A more detailed explanation can be found at correction factor.

(5) Strength of Schedule (MOV -> average)

A team's strength of schedule (SOS) is based on evaluating the strength of opponents. A simple method is to average all opponents' power ratings. The higher an opponent's power rating, the higher the SOS. Only games played count. A more detailed explanation can be found at SOS.

(6) Strength of Schedule (MOV -> weighted-average)

Instead of simply averaging opponents' power ratings, by taking the square or higher exponent of the s power rating, then tougher opponents are accentuated and lesser opponent's power ratings reduced. A more detailed explanation can be found at SOS.

(7) Strength of Schedule (RPI)

A different method, used by the NCAA, is to evaluate opponents' won-loss records and their opponents' won-loss records. A more detailed explanation can be found at SOS.

(8) Win-Loss Percentage (Total)

Wins and losses for all games count regardless of the opponent's division. A more detailed explanation can be found at win-loss percentage.

(9) Win-Loss Percentage (Division)

Only games within the division count. A more detailed explanation can be found at win-loss percentage.

(10) Win-Loss Percentage (total, later games more important)

Wins and lsses are modified, depending when the game was played, i.e., the beginning or end of the season. A more detailed explanation can be found at win-loss percentage.

(11) Win-Loss Percentage (total, road games more important)

Wins and losses are modified depending where the game was played (home, away or neutral). A more detailed explanation can be found at win-loss percentage.

(12) Championship Bonus Point

When a team wins a championship, they are accorded recognition with bonus points. The points will vary depending on the importance of the championship. For example, a state championship is more important than one at lower level.

(13) Ratings Percentage Index

The NCAA uses the Ratings Percentage Index (RPI) in evaluating team performance for post-season tournament selections. It is based strictly on the won-loss records of all teams and has three components. The first is a team's win-loss percentage, the second is the average win-loss record of all opponents, and the third is the average win-loss percentage of all opponents' opponents. A more detailed explanation can be found at Ratings Percentage Index.

(14) Significant Wins Based on RPI

If a team with a lower RPI defeats its opponent, then it is considered a significant win.

(15) Significant Losses Based on RPI

If a team with a higher RPI loses to its opponent, then it is considered a significant loss.

(16) Quality Wins (Polls)

Quality wins awards points for defeating teams of a certain ranking. In this case, the ranking is based on polls. A more detailed explanation can be found at quality wins.

(17) Quality Wins (MOV)

Quality wins awards points for defeating teams of a certain ranking. In this case, the ranking is based on computer ratings. A more detailed explanation can be found at quality wins.

(18) Quality Wins (RPI)

Quality wins awards points for defeating teams of a certain ranking. In this case, the ranking is based on RPI. A more detailed explanation can be found at quality wins.

(19) Polls

Polls are based on expert opinions of coaches and sportswriters. Their rankings are used in computing other criteria such as strength of schedule. A more detailed explanation can be found at Polls.

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