I'm not a math major, but now I have a freshman, and RPI matters when they're on the edge for tournament time.
I don't know if anyone knows much about the RPI calculation, but they seem to put a lot of emphasis on Road Wins/Losses (Road Win counts 1.3). Is it really that significant in softball?
Re: NCAA RPI
Posted by Sergey Brin on April 20, 2026, 2:43 pm, in reply to "NCAA RPI"
This information is available on the world wide web. But I'm lonely and unsober, so lemme lend a hand
Three primary components to RPI:
25% your own record (D1) 50% your opponents record (D1) 25% your opponents' opponents' record (D1)
At home, wins are worth 0.7 and losses worth 1.3. On road, wins are worth 1.3 and losses are worth 0.7. Those all get factored into the weightings.
So, if you're asking if it's "significant" from a quantitative perspective, that's a math answer. If you're asking if home and road games are significant in some other way, pray tell more
Re: NCAA RPI
Posted by Illinois Coaches on April 20, 2026, 3:34 pm, in reply to "Re: NCAA RPI"
Illinois Coaches Association should put this out instead of their guesstimates. Or MaxPreps
Re: NCAA RPI
Posted by @Illinois Coaches on April 21, 2026, 7:48 am, in reply to "Re: NCAA RPI"
The NCAA has a far larger sample of non-conference games that can affect the outcome. HS would be entirely based on the conference's relative strength. That being said, I'd love to see it, but I just don't have the math chops.
Re: NCAA RPI
Posted by DuKane RPI via Claude on April 21, 2026, 12:16 pm, in reply to "Re: NCAA RPI"
This was too tempting and I had to try! Claude to the rescue...
So here's what I did - I pointed Claude to MaxPreps for the DuKane Conference and asked it to generate an RPI. I used the same formula described here, with your win/loss, your opponents win/loss and your opponents' opponents' win/loss. I also layered in the home/away dynamics (0.7/1.3). Then I let Claude work - it took about 75 minutes. Here's what it spit out:
There are too many digits for me to copy, and it's not important with such a small sample size - but it shows that this can be done! (Although, maybe I burned a million tokens doing it?!)
Like I said, it's WAY too early and this doesn't matter yet, but it was also fascinating to see the commentary Claude created:
"St. Charles East ranks #1 despite having the 3rd-best conference record (2-1) and a conference loss to Lake Park. Their enormous non-conference schedule — 17 completed games featuring strong opponents like Marist (16-0), Lincoln-Way East (12-4), Stillman Valley (12-2), and Lemont (12-4) — produces a very high OWP (.6326) and OOWP (.6397), which the model rewards heavily.
St. Charles North ranks #2 with the only perfect record (9-0) and a perfect WP (1.000). They lead the conference outright at 3-0, but their schedule lacks the same quality depth as SCE's, keeping their OWP lower (.5221). They still score very well overall."
I know that this information is gong to be weaponized now, but that's not what I was trying to prove - only that this can be done, and it would be tons of fun if it were regularly available!!
Re: NCAA RPI
Posted by Claude on April 21, 2026, 2:19 pm, in reply to "Re: NCAA RPI"
It got wrong the STCE loss (it was to North, not LP), but it's still pretty interesting that it can crunch this stuff!!
Re: NCAA RPI
Posted by @Mr Brin on April 20, 2026, 3:28 pm, in reply to "Re: NCAA RPI"
Just asking if home field is that much of an advantage. In the daughters' conference, the better team seems to win no matter where they're playing.
