If you've heard coaches and athletic directors talking about RPI this season, you're not alone in wondering what it means. The Ratings Percentage Index is the formula that determines which North Carolina high school football teams make the playoffs and how they're seeded, and understanding it can change how you view every game on the schedule.
The Formula Behind the Rankings
The NCHSAA uses MaxPreps' RPI calculation to rank every team in the state. The formula weighs three factors:
RPI = (0.4 × WP) + (0.4 × OWP) + (0.2 × OOWP)
Breaking that down in plain English: 40% of your RPI comes from your own winning percentage, 40% comes from your opponents' winning percentage, and 20% comes from your opponents' opponents' winning percentage.
Why Winning Percentage Is Only Part of the Story
Here's what makes RPI different from simply looking at win-loss records: strength of schedule matters tremendously. In fact, it accounts for 80% of the formula.
A team that goes 8-2 against tough competition could have a higher RPI than a team that goes 9-1 against weaker opponents. That's because when you play better teams, their winning percentages boost your OWP even if you lose to them.
This creates an interesting dynamic for coaches building their schedules. A close loss to a playoff-caliber opponent might hurt your RPI less than you'd think, while a win against a winless team provides minimal benefit.
Point Differential Doesn't Count
One of the most important things to understand about RPI: margin of victory is irrelevant. Whether you win by one point or run up the score to 50, the formula treats it exactly the same.
This removes any incentive for teams to pile on points and keeps the focus on simply winning games, regardless of the margin.
The Precision of the System
MaxPreps displays RPI values to four decimal places, which means you might see rankings like 0.6247 or 0.5891. If two teams are tied at four decimal places, the system extends to more decimal places until it breaks the tie.
This precision ensures that every team has a unique ranking position, eliminating the need for tiebreaker procedures.
Out-of-State Games: Navigate Carefully
Teams that schedule out-of-state opponents need to understand how those games affect their RPI.
Border States Matter Most: Games against opponents from Virginia, South Carolina, Georgia, and Tennessee count fully in the RPI calculation—but only if the opponent has a verified MaxPreps account with their complete schedule entered. Schools must take responsibility for ensuring their out-of-state opponents' data is accurate on MaxPreps.
Non-Border States Have Limitations: If you play a team from a state that doesn't border North Carolina, the calculation changes. Your opponent's actual winning percentage counts, but each of their opponents is automatically assigned a .500 record in the formula. This dramatically reduces the RPI value of these games.
For example, if you beat a 10-0 team from Florida, you'd get credit for defeating a 1.000 team, but in calculating your OWP and OOWP, all of that Florida team's opponents would be treated as .500 teams, even if they actually went undefeated or winless.
What This Means for Fans
When you're watching games this season, RPI adds another layer to consider. That early-season loss to a strong opponent? It might not be as damaging as it seems if that opponent keeps winning. The running clock blowout against an overmatched team? It helps your record but does little for your RPI.
The system rewards teams that challenge themselves and play competitive schedules. As you track your favorite team's playoff chances, look beyond just wins and losses - pay attention to how their opponents are performing throughout the season.
Understanding RPI transforms how you follow high school football in North Carolina. It's not just about your team's record anymore; it's about the entire web of competition across the state and how every game contributes to the mathematical calculation that will determine who plays in November.
.png)
