How Rankings Are Determined?

🌍 Foundation: The World Rugby Model

The World Rugby Rankings system, established in 2003, is designed to reflect the current strength of international rugby teams. Key features include:

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• Points Exchange System: Teams exchange points based on match outcomes. A win results in the winning team gaining points and the losing team losing the same amount.

• Match Result: The outcome (win, loss, or draw) directly affects the points exchanged.

• Margin of Victory: Wins by more than 15 points yield a higher points exchange, emphasizing dominant performances.

• Strength of Opposition: Defeating a higher-ranked team results in a greater points gain, while losing to a lower-ranked team leads to a more significant points loss.

• Home Advantage: The home team is considered to have a three-point advantage, acknowledging the benefits of familiar conditions and local support.

• Match Importance: Certain matches, like World Cup games, carry more weight, with points exchanges doubled to reflect their significance.

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This system ensures that rankings are dynamic and reflective of recent performances, encouraging teams to consistently perform at their best.

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🏫 Adapting for Schoolboy Rugby: The House Rugga Approach

Recognizing the unique dynamics of schoolboy rugby in South Africa, the House Rugga system incorporates the foundational principles of the World Rugby model with specific adaptations:

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• Initial Rankings: Schools carry over their rankings from the previous season. New entrants start with a base rating of 40.00 points, aligning with the World Rugby approach for new teams.

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• Home Advantage: Given the variability in school match venues, home advantage is generally excluded. However, during festivals where a team plays at home, a +3 point advantage is applied, mirroring the World Rugby system's treatment of home advantage.

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• Points Exchange Mechanics:

  • Within 10-Point Ranking Difference: Both teams can gain or lose points based on the match outcome and margin.

  • Beyond 10-Point Ranking Difference:

    • If the higher-ranked team wins, no points are exchanged.

    • If the lower-ranked team wins, they gain a significant number of points, while the higher-ranked team loses a substantial amount. This adjustment ensures that unexpected outcomes are appropriately reflected in the rankings.

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• Weighting Factors: The system employs variable weightings based on the opponent's rank and the match result:

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    Wins by 16+ Points:

    • Opponent ranked >50: 0.10

    • Opponent ranked 31–50: 0.12

    • Opponent ranked 11–30: 0.15

    • Opponent ranked ≤10: 0.20

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• • Wins by ≤15 Points or Draws:

    • Opponent ranked >50: 0.05

    • Opponent ranked 31–50: 0.08

    • Opponent ranked 11–30: 0.10

    • Opponent ranked ≤10: 0.15 (Draws: 0.12)

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This nuanced approach ensures that the rankings accurately reflect team performances, considering both the strength of the opposition and the nature of the victory.

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🧮 Practical Examples

Example 1: Paul Roos (88.4 pts) v Grey College (91.6 pts)

• Ranking Difference: 3.2 points (within 10-point threshold)

• Outcome: Paul Roos wins by 18 points

• Calculation:

  • Points Exchange = (10 + Opponent's Points - Your Points) × Weight Factor

  • = (10 + 91.6 - 88.4) × 0.20

  • = 13.2 × 0.20

  • = 2.64 points gained by Paul Roos

  • Grey College loses 2.64 points

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Example 2: Paul Roos (88.4 pts) v Pretoria Boys High (62.5 pts)

• Ranking Difference: 25.9 points (beyond 10-point threshold)

• Outcome 1: Paul Roos wins

  • No points are exchanged; the result aligns with expectations.

• Outcome 2: Pretoria Boys High wins

  • Pretoria Boys High gains a significant number of points.

  • Paul Roos loses a substantial number of points.

  • This reflects the unexpected nature of the result and adjusts the rankings accordingly.

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⚖️ Ensuring Fairness and Accuracy

The House Rugga system, while inspired by the World Rugby Rankings, incorporates specific adjustments to address the unique aspects of schoolboy rugby:

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• Dynamic Adjustments: By considering both the margin of victory and the strength of the opposition, the system ensures that rankings are responsive to actual performance levels.

• Protection Against Anomalies: The 10-point threshold mechanism prevents significant ranking shifts due to predictable outcomes, maintaining stability in the rankings.

• Encouragement of Competitive Matches: Teams are incentivized to play against similarly ranked opponents, promoting competitive fixtures and overall development.

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By blending the structured approach of the World Rugby system with tailored modifications, the House Rugga rankings provide a fair, transparent, and accurate reflection of schoolboy rugby performances in South Africa.