How Our Ratings Work

KRACH is a pure win/loss rating built on the same mathematical foundation used in chess ratings and sports analytics. It answers the question: "Based on who you beat and who those teams beat, how good are you really?"

How it works

Every team starts with an equal rating. The algorithm then asks: if Team A (rated Ka) plays Team B (rated Kb), the expected probability of A winning is Ka / (Ka + Kb). Ratings are adjusted repeatedly — hundreds of iterations — until each team's expected win total exactly matches their actual win total. That convergence point is the final KRACH score.

Because the math chains through every opponent and every opponent's opponent, a team's KRACH automatically reflects the strength of its schedule — no manual adjustment needed.

Reading the numbers

• KRACH — The core rating, scaled so all teams in a division sum to 10,000. Higher is better.
• SOS — Strength of Schedule: the average KRACH of your opponents, weighted by games played.
• Adj. KRACH — A reliability-adjusted version that pulls teams with very few games played closer to average, so a 3-0 team early in the season isn't ranked above a 20-2 team.

PairWise is the system used by NCAA Division I hockey to select and seed teams for the tournament. It answers the question: "In a direct comparison between any two teams, which one has the stronger case?"

How it works

Every team is compared head-to-head against every other team in the division using three criteria, each carrying equal weight:

1. RPI comparison — Which team has the higher Rating Percentage Index (see below).
2. Head-to-head record — Which team won the majority of games played directly between the two teams.
3. Record vs. common opponents — Which team performed better against the opponents both teams share.

The team that wins 2 or 3 of those criteria earns a PairWise Win. A team's final PWR Points = PairWise Wins + 0.5 × PairWise Ties (when all three criteria are split). Teams are ranked by PWR Points descending.

What is RPI?

RPI (Rating Percentage Index) blends three win-percentage numbers: 25% of your own winning percentage + 50% of your opponents' average winning percentage + 25% of your opponents' opponents' average winning percentage. This weighting means that who you beat matters almost as much as that you won.

Reading the numbers

• PairWise # — Your rank by PWR Points among all teams in the division.
• PairWise PWR — Raw PWR Points (wins + 0.5 × ties in pairwise comparisons).
• PairWise RPI — Your RPI score (roughly 0.0–1.0; higher is better).

NPI is an iterative rating that combines your winning percentage with a schedule-adjusted strength of schedule. It answers the question: "How does your win percentage hold up when we account for who you played — and who they played?"

How it works

The formula is: NPI = (Win% × 25%) + (Strength of Schedule × 75%)

The 75% weight on Strength of Schedule makes NPI much more sensitive to schedule difficulty than a plain winning percentage. Crucially, your opponents' SOS component uses their NPI ratings — which in turn depend on their opponents' NPI ratings — making the whole thing iterative. Ratings are recalculated in a loop until they stabilize.

A team that goes 10-0 against weak competition will score lower on NPI than a team that goes 8-2 against strong competition.

Reading the numbers

• NPI # — Your rank by NPI score among all teams in the division.
• NPI — The raw NPI score on a 0–100 scale. Higher is better.
• NPI SOS — The strength-of-schedule component that fed into your NPI.

SRS (used by myhockeyrankings.com under the name "Average Goal Differential + Strength of Schedule") is the only rating here that uses goals scored rather than just wins and losses. It answers the question: "How many goals better or worse than average are you, after accounting for how tough your schedule was?"

How it works

The formula is: SRS = AGD + SOS

• AGD (Average Goal Differential) — The average margin of victory or defeat across all your games, capped at ±7 goals per game. The cap prevents a single blowout win from inflating a team's rating.
• SOS (Strength of Schedule) — The weighted average SRS rating of your opponents, weighted by how many games you played against each one.

Like KRACH and NPI, SRS is iterative — your opponents' ratings depend on their opponents' ratings — and it loops until the ratings converge. Once converged, an additive shift is applied so the top-rated team in the division lands at exactly 99.99.

Example: A team that wins every game 5–0 against average opponents has an AGD of +5. If their schedule was slightly below average (SOS = −0.5), their SRS would be 4.5 before normalization. A team that wins 3–2 every game but only plays elite opponents (SOS = +3.0) could rank higher despite a smaller margin of victory.

Reading the numbers

• SRS # — Your rank by normalized SRS rating in the division.
• SRS — The normalized rating (top team = 99.99). All other teams are shifted by the same offset, so the gaps between teams remain meaningful in goals-per-game units.
• SRS AGD — Your Average Goal Differential per game (capped at ±7).
• SRS SOS — The strength-of-schedule component in goals-per-game units.

All four ratings are updated every Monday morning and recalculated whenever new game scores are imported. Ratings only include games played through the current week's cutoff date.