Comparing Advanced Metrics to NCAA 1-68 Seed List: 2018 Edition

The NCAA added six metrics (KenPom, Sagarin, BPI, KPI, RPI, and ESPN Strength of Record) to the team sheets prior to the 2017-18 season.  For the fourth straight year, I have charted how the committee’s 1-68 NCAA Tournament seed list compared to those metrics.  With the metrics now on the team sheet, there is a level of circular logic that comes with it, making for an imperfect comparison.

These (and other) metrics are intended to quantify different things. Some metrics are more predictive in nature – intended to rank the quality of a team (i.e. KenPom, Sagarin, BPI). Other metrics are results-based and looking backwards at a team’s resume and performance (i.e. KPI, RPI, and ESPN’s Strength of Record). Just because one ranking is further from the seed list doesn’t make it incorrect.

This comparison is not intended to rank rankings, but rather analyze how the 1-68 seed list compares. No system is perfect, and there are several others (and several very smart people) that are well-written, sound, and progressive. Predictive-based metrics are often not intended to project who should make the NCAA Tournament. There is no claim here that any metric is “right” or “wrong”.

How Metrics Compared to Actual 68-Team Field in 2017-18

The team who is “supposed to win” a game won 77% of the time this season. Upsets and outliers happen and matter. Many of the most quality of wins are outliers.  Ultimately, the results have to matter.  The best win of the season according to KPI was Virginia Tech’s win at Virginia (1.09 KPI), followed by Villanova’s win at Xavier on February 17.

2015 Edition | 2016 Edition | 2017 Edition

Teams Matched to the NCAA Tournament 1-68 Seed List:

67, KPI
63, ESPN Strength of Record
62, RPI
61, KenPom
61, Sagarin

Margin of Difference in Rankings (This is measured as the difference between the given metric and the actual 1-68 List only for teams correctly projected in the field):

3.00, ESPN Strength of Record
3.21, KPI
3.46, KenPom
3.77, Sagarin
3.97, ESPN BPI
5.16, RPI

Teams Matching Actual 1-68 Seed List Within Zero, One, or Two Spots (0.5 seeds):

37, KPI
35, ESPN Strength of Record
33, RPI
29, KenPom
26, Sagarin

Teams with Seed Difference of 10 or More Spots (equivalent of 2.5 seed lines) from Actual 1-68 List:

3, KPI
4, ESPN Strength of Record
4, KenPom
5, Sagarin
10, RPI

Full data on how metrics compared to actual 68-team field:

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