There are a lot of rankings systems out there. They all have their good and their bad elements, including mine. Additionally, there are a few ways to view rankings.
1. The AP and Coaches Poll start with a ranking. Based on this initial ranking, teams move up and down throughout the season based on wins and losses.
2. Based on a number of factors, an independent ranking can be created for purposes of seeding. This is why I developed the Cro-Curve, similar to the S-Curve that the selection committee uses.
3. Based on a number of factors, an independent ranking can be created to predict the future outcome of games. This is Crotistics.
My goal was to create a system that can be the best at predicting game results. The factors that go into this prediction are some bias-free metrics as well as some additional custom metrics. I don’t believe in the notion that human judgement is not a part of ranking teams. At some point there is a person deciding what formula to use, or how to weight wins, or how to calculate a strength of schedule.
ESPN’s BPI, for example, weights games with injured players differently. But how is that weighting determined? It’s a person deciding. Whether my rankings are valid or not, I have decided what I believe to be the best weighting at predicting future games. The metrics I use are:
PURE W/L: This is the overall Win/Loss record for a team. It only counts games against Division I opponents, as do all of my metrics.
WIN STRENGTH: This is a formula that is a recursive calculation based on teams you have played to date. Currently there are 351 teams in Division 1. If you have beaten the #1 ranked team you get 351 points. This is a declining score, so if you beat the #351 team, it is only worth 1 point. Losses work in reverse. A loss to the #1 ranked team is only -1 point, while a loss to the #351 team would be worth -347 points. The average of the sum of these points is a team’s “Win Strength”.
SOS: Strength of Schedule is calculated in so many different ways. Should you take into account who your opponents have played? To me, a Strength of Schedule must capture the quality of teams you’ve played. This is another recursive calculation. I use a geometric average instead of an arithmetic average. What does this mean? This means that if you’ve played the #1 team and the #100 team, your strength of schedule is viewed as being more difficult than a team that has played the #30 team and the #40 team. An arithmetic average views the second example as the more difficult schedule.
MARGIN OF VICTORY: I am aware that teams may “Run up the score”, but in most cases, a team that beats another by 25 is better than a team beating that same opponent by 1. At this point, there is not a respected system out there that does not take Margin of Victory into account.
HOME ADVANTAGE: Beating a team on the road should be worth more than beating the same team at home. Team averages are calculated based on the number of games they’ve played at home, away, and on a neutral floor and applied to the overall ranking.