The NCAA decided to make a drastic change to its Division I men’s basketball ranking system when it introduced the NCAA Evaluation Tool prior to the start of the 2018 to 2019 season.
After much deliberation over the past few months by the Division I NCAA men’s basketball committee, basketball analysts, statisticians and coaches, the NET was set to replace the previous ranking system, the Ratings Performance Index. RPI has been the ranking system for all NCAA men’s basketball divisions since 1981 and has been the ranking system for NCAA women’s basketball since 1984.
This is the second straight year the NCAA has attempted to make the ranking system more accurate. Before the 2017 to 2018 season, the NCAA introduced a quadrant system that gave more weight to wins away than wins at home, no matter the opponent’s ranking.
RPI was based on a simple equation that determined the rating of teams relative to other teams. Essentially, it was only composed of three factors: a team’s Division I winning percentage (25 percent), a team’s opponents’ Division I winning percentage (50 percent) and a team’s opponents’ opponents’ Division I winning percentage (25 percent). The RPI ranked teams purely on their play against teams that are harder to beat.
The NET brings more variables into the equation, to attempt to make the system more accurate. These factors could impact your favorite Division I teams’ rankings.
Strength of Schedule
The strength of schedule that a team has throughout its season will now play a factor in its ranking. The change will give teams that play higher ranked opponents in a season a better chance at a high ranking because of the above-average level of competition that they will face. It will also be more lenient on the losses teams may accumulate over the season.
Team Value Index
Team Value Index is a new statistic that evaluates the quality of a team’s wins and losses. The algorithm is based on the outcome of the game, quality of the opponent, the game’s location and the winner of the contest. Wins against higher ranked opponents will have a greater impact on a team’s ranking than wins against lower ranked opponents. Wins on the road will have a greater impact on this index, as will losses at home.
Net Efficiency is a team’s offensive efficiency minus its defensive efficiency. Offensive efficiency is influenced by a team’s shot attempts, offensive rebounds, turnovers, free throw percentage and average points per possession. Defensive efficiency is influenced by all the same factors but of the team’s opponent. Playing well offensively as well as defensively will generate a high net efficiency.
Winning Percentage and Adjusted Winning Percentage
A team’s Division I winning percentage, like in the RPI, will still play a factor in a team’s ranking. The NET introduces the new adjusted winning percentage which weighs the outcomes of games based on its location. The adjusted winning percentage awards teams for road wins and penalizes teams for home losses. A road win is worth 1.4 of a neutral zone win (a game played at neither team’s home stadiums) while a home win is only worth 0.6 of a neutral zone win. Similarly, a home loss is worth 1.4 of a neutral zone loss while a road loss is worth 0.6 of a neutral zone loss.
Margin of Victory
Defeating teams by a comfortable margin of victory will now net a team a better chance at a higher rank, encouraging teams to play their hardest all 40 minutes on a court. The margin of victory is capped at 10 to discourage a team from running up the score in an already decided game with time left on the clock. Overtime games, regardless of end score, will end in a margin of victory of plus one for the victors and minus one for the defeated.
The NCAA hopes that this new rating system will result in more exciting matchups in the March Madness tournament with the playing field more leveled than it has been before when RPI was in place.
A version of this article appeared in the Monday, Dec. 3 print edition. Email Zach Han at [email protected]