The Road to Oklahoma City starts here.


D1Softball and 6-4-3 Charts introduce the Diamond Sports Ranking (DSR)


A new approach to ranking college softball teams

In college sports, rankings play a crucial role in determining post-season playoff seedings and the perception of a team’s overall competitiveness. D1Softball is excited to announce the launch of one of the latest innovations in this field – the Diamond Sports Ranking (DSR). DSR is a revolutionary approach to ranking teams that provides enhancements not found in the traditional Ratings Percentage Index (RPI). Let’s look at why DSR was created, how it works, and how it improves upon RPI.


What is the Diamond Sports Ranking and why was it created?
The Diamond Sports Ranking is a new method of ranking college softball and baseball teams intended to give a more robust representation of team performance than provided by RPI. Developed by 6-4-3 Charts in collaboration with D1Softball and D1Baseball, DSR is grounded in established statistical methodologies informed by insights from experts in college softball and baseball.

What’s wrong with RPI?
DSR was created to address limitations in the RPI system. These can result in skewed rankings and create a late-season incentive for teams to cancel non-conference games against lower-ranked opponents.

The major criticisms of RPI focus on three main points:

When you win, you lose: The biggest concern with RPI is that a team can lose RPI points even if they win a game, simply because of the quality of their opponent. Not only does this create an incentive to avoid playing weaker teams, but the heavy weight placed on strength of schedule gives an unfair advantage to teams from major conferences. The RPI rankings of weaker teams from major conferences are boosted by their conference affiliation, not just their on-field performance. Very good teams from non-major conferences are likewise penalized simply by stepping onto the field in required conference games.

Back to the future: Another criticism of RPI is that the value of a win or loss in RPI can change based on how the opponent performs in subsequent games. This post-game adjustment ignores that players and teams develop and change over the course of a season; and as a result, the context of when a game took place matters. An extreme example of this problem occurs when a lower-ranked team earns an upset victory over a more highly ranked team whose season later takes a downward turn due to an injury to a key player or players. RPI devalues that original upset win, even though it took place when the higher-ranked team was at full strength.

More isn’t better: RPI treats all wins and losses equally, regardless of the margin of victory or defeat. This ignores the difference between close games and blowout victories.

How does DSR improve upon RPI?
DSR addresses the limitations of the RPI system through two fundamental principles:

A win is always good: When a team wins they earn points, and when they lose they lose points. The quality of a win or loss is reflected by adjusting the number of points exchanged based on opponent quality, expected win probability, margin of victory, and game location.

The value of a win or loss doesn’t change after the last out: Unlike RPI, the value of a win or loss in DSR is fixed at the time it occurs and doesn’t change based on subsequent outcomes.

How does DSR work?
Teams earn DSR points based on four factors:
Win Quality – how good was the team you beat? 
DSR determines the quality of the team defeated using a formula based on runs scored and runs allowed. This makes sense, since the more runs you score and the fewer you allow, the more likely you are to win games. Think of it this way: if a team never scores a run, its expected winning percentage is 0% since at least one run is needed to win. And for the same reason, if a team never allows a run, its expected win percentage is 100%. Both the opponent’s quality as well as the quality of their conference are measured and incorporated. (Win Quality weighting: 61% of the total.)

Win Expectancy – were you “supposed” to win the game? 
Teams who are expected to win a game get fewer points than teams who win when they aren’t supposed to. Because the number of points gained by the winning team is equal to the points lost by the losing team, DSR rewards a big upset win and at the same time penalizes the favored team for the unexpected loss. (Win Expectancy weighting: 29% of the total)

Margin of Victory – was it a close game or a blowout?
Unlike RPI, DSR accounts for a team’s margin of victory by providing more points for games won by multi-run margins than those won by a single run. In order to minimize the potential incentive for running up the score, the margin of victory is capped at 10 runs. (Margin of Victory weighting: 9% of the total)

Location – where was the game played?
Wins on the road generate more points than home wins. Using historical data trends across the past five seasons, DSR rewards teams for the added difficulty of winning away from home. (Location weighting: 1% of the total)

Where can I find the DSR Rankings?
The DSR rankings are now live on the D1Softball website under the Rankings tab.

On the DSR rankings page, you can see the overall DSR rank as well as the components that go into the outcome. For an explanation of each factor, simply hover over the column header. 

You can also sort the table by the various headers; for example, if you want to see teams ranked by Strength of Schedule (SOS), you can sort on the SOS column. That will also give you a quick view of how SOS and DSR rank compare. And to quickly find a specific team, just type their name into the search bar.

The Diamond Sports Ranking (DSR) represents a significant advancement in the realm of college softball rankings, offering a system tailored to the modern game. Building on established statistical methodologies and developed in collaboration with experts in the college game, DSR provides the softball community with a more sophisticated and equitable way to evaluate the on-the-field performance of each team.

More Resources on DSR
• DSR Explained (written by 643 Charts)
The Initial Launch of DSR (written by 643 Charts)