How Rivalries Are Ranked: This is a weighted formula designed to identify the strongest rivalries — not simply the opponents with the most meetings. Approximate emphasis: 32% weighted meeting volume (with playoff games counting heavier), 22% series parity / competitiveness, 18% average scoring margin (closer games rank higher), 12% playoff frequency and repeated postseason collisions, 8% longevity across eras, and 8% recency / current relevance. The formula also applies small penalties to tiny sample sizes and highly one-sided series.