The Power Rankings provided here use two different calculated values, Offensive Power Rating (OPR) and Calculated Contribution to Winning Margin (CCWM). I came across these when I was a scouting/alliance selection mentor for an FRC team. These ratings are calculated based on the match results of teams at competitions and provide an objective way to compare teams to each other. I believe the best information about teams is gathered on the field, in the pits, and in discussion with team members. There are some teams, however, that you may not ever meet on the field or that you would like information about prior to a competition. In these situations I believe these ratings can be helpful. For more information about how these values are determined please see http://www.team2834.com/team_documents/Team2834_ScoutingDatabasePresentation_2012.pdf, as this was the basis for my calculations. Below is a summary of how to interpret OPR and CCWM.
The Interpretation of OPR
OPR does not predict what a team can score. It is the calculated contribution by that team on average to all the matches they were involved in to their alliance partners. A team that has high OPR score means that every time they are on the field, good things happen to that alliance meaning high score. Some of the possibilities are:
1) Their robot scores a lot of points.
2) Their presence allows their alliance partner to score a lot of points which they don't normally do as well.
3) They have on average stronger partners and weaker opponents by the luck of the draw than other teams.
A low OPR is just the opposite.
The Interpretation of CCWM
CCWM is the calculated contribution to the winning margins of the matches the team was involved in. A team that has high CCWM means that every time they are on the field, good things happen to that alliance and in this case it means winning by a big margin. Some of the possibilities are:
1) They score more points on others than others score on them.
2) Their presence allows their alliance to score more points on others than others score on them. This could be from playing defense so their alliance partner can score more.
3) They do not incur many penalties.
4) They have on average stronger partners and weaker opponents by the luck of the draw than other teams.