What is RPI? Explaining softball rankings system ahead of NCAA Tournament bracket reveal
It's here. Welcome to Selection Sunday for the 2025 NCAA Softball Tournament.
With half of the field already completed by automatic bids from conference tournaments, the remainder of the 64-team field for the NCAA Softball Tournament will be announced at 7 p.m. ET, signaling the official start of the sport's marquee tournament.
And for those that miss out on playing for a spot in the Greatest Show on Dirt, that is the Women's College World Series, one of the more notable questions that will be asked is, what was that team's RPI ranking? Not how that team did in their respective conference tournament. But instead, their respective RPI ranking.
As it has for much of the season in the national polls, the SEC has a rather healthy showing in the top 10 of the RPI rankings going into Selection Sunday, as Greg Sankey's conference holds eight of those 10 spots — perhaps a foreshadowing of who will be having home field advantage until Oklahoma City and the WCWS.
But what exactly is the RPI ranking system and how does it impact a softball team?
Here's what you need to know about the NCAA's RPI rankings and more ahead of Selection Sunday for the NCAA Softball Tournament:
What is RPI? Explaining NCAA softball ranking system
The RPI ranking system in softball – Rating Percentage Index – is a data-driven sorting system used by the NCAA Tournament selection committee when considering the field.
Similar to baseball, the RPI ranking system is based on a team's strength of schedule. The RPI ranking system is used for the majority of the NCAA's sports, such as volleyball, soccer and baseball, but not men's and women's basketball, which use a NET ranking system.
There are three key factors that are used in RPI rankings:
- Team's own winning percentage
- Opponent's winning percentage
- Opponent's opponent's winning percentage
Softball RPI rankings on Selection Sunday
Here's a list of the top 16 teams in the country per the NCAA's RPI rankings, which theoretically would result in the top 16 regional host site locations:
Ranking reflective of games through Thursday, May 8
- Texas A&M
- Florida
- Florida State
- LSU
- UCLA
- Arkansas
- Oklahoma
- Texas
- South Carolina
- Tennessee
- Duke
- Arizona
- Clemson
- Virginia Tech
- Stanford
- Auburn