I know it is football SZN and everybody is excited for that, but the NCAA has announced that college basketball will no longer use the RPI metric. The metric has been used to help decide tournament teams since 1981. The move to ditch the metric is long overdue and many are excited for it.
What is the RPI system?
The RPI (Rating Percentage Index) system is a ranking metric that uses wins, losses, and strength of schedule to rank teams. The formula is:
RPI = (WP * 0.25) + (OWP * 0.50) + (OOWP * 0.25)
Yeah I know that is a bunch of nonsense that makes no sense so let me explain. Basically WP means Winning Percentage, OWP is Opponents Winning Percentage, and OOWP is Opponents’ Opponents’ winning Percentage.
There is a bit of a catch though. Usually WP is calculated by dividing the number of wins a team has by the number of games they have played. But the RPI counts a home win as .6 wins, a road win counts as 1.6 wins, and a neutral site win counts as 1 win. For losses it is reversed, a home loss counts as 1.4, a road loss is .6, and a neutral site loss is still 1 loss.
So the WP and OOWP counts for 25% of the RPI grade each and the OWP counts for 50%.
Why is it being abandoned?
The system is outdated and basically counts a road win against the 100th best team the same as a road win against the best teams. It also doesn’t factor in margin of victory either. So whether a team wins against the 75th best team by two or the 2nd best team by 20, it would count as the same. But not only is the system flawed, the amount that it was used to factor into the tournament rankings was way too high.
What is replacing the RPI then?
The metric that is going to replace the RPI is the NCAA Evaluation Tool, or NET for short (yes this was probably planned). The NET system will use a combination of game results, strength of schedule, game location, scoring margin, net offensive and defensive efficiency, and the quality of wins and losses. It will take into consideration the margin of victory, unlike the RPI, but it is only up to ten bonus points to discourage teams running up the score unnecessarily and showing bad sportsmanship.
Introducing the NCAA Evaluation Tool (NET), a modernized metric replacing the RPI this season.
— NCAA March Madness (@MarchMadnessMBB) August 22, 2018
MORE:
👉 https://t.co/6omYudsWTK pic.twitter.com/Dwlq4RWRSv
The quadrant system will still be used to help evaluate teams but instead of using the RPI rankings to determine the quadrants, the NET metric will also be used in its place.
If you don’t know what the Quadrant system is then here is a basic rundown:
- Quadrant 1 Wins: Home 1-30, Neutral 1-50, Away 1-75
- Quadrant 2 Wins: Home 31-75, Neutral 51-100, Away 76-135
- Quadrant 3 Wins: Home 76-160, Neutral 101-200, Away 135-240
- Quadrant 4 Wins: Home 161-351, Neutral 201-351, Away 241-351
NET versus RPI will be split like an atom over the next few weeks, but here's one important thing to remember: The best way to still build an NCAA Tournament resume is to beat teams that are projected to be in the NCAA Tournament.
— Jon Rothstein (@JonRothstein) August 22, 2018
So basically the RPI is being replaced by the NET to help the rankings become more efficient and also help rank teams more fairly.