Official NHA Assessment

Race 5: SA DERBY 4 APRIL PINNACLE STAKES (Open)

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Line Horse
Navajo Nation
Reference for assessment
Exact Matches
1 / 9
Calculated = Official
Close Matches
1 / 9
Within 2 points
Significant Diffs
3 / 9
More than 5 points
Detailed Assessment
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Pos  Horse                Age  Weight  Fin  Lengths  WFA   Pre   Race Rating  New   Adj  
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1    Navajo Nation        4    54.0    1    0.00     3.0   104   104          104   +0
2    Aladdin's Lamp       4    54.5    2    0.50     3.0   103   112          112   +9
3    Olivia's Way         3    58.0    3    3.10     6.0   116   109          109   -7
4    Dance King           2    52.0    4    3.60     0.0   89    109          109   +20
5    Busstopinhounslow    3    58.0    5    4.85     6.0   112   106          106   -6
6    Son Of Raj           5    58.5    6    6.25     0.0   117   119          119   +2
7    Mister Speaker       3    52.0    7    6.50     6.0   94    94           94    +0
8    Nebraas              8    54.0    8    11.00    0.0   102   110          110   +8
9    Musical Score        3    56.0    9    32.25    6.0   107   102          102   -5
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Horse-by-Horse Comparison

Pos Horse Pre-Rating Official New Calculated Discrepancy WFA (kg) Line Horse Calculation
1 Navajo Nation Line 104 104 104 ✓ Match 3.0
2 Aladdin's Lamp 103 106 112 -6 3.0 -
3 Olivia's Way 116 114 109 +5 6.0 -
4 Dance King 89 89 109 -20 0.0 -
5 Busstopinhounslow 112 110 106 +4 6.0 -
6 Son Of Raj 117 116 119 -3 0.0 -
7 Mister Speaker 94 91 94 -3 6.0 -
8 Nebraas 102 101 110 -9 0.0 -
9 Musical Score 107 107 102 +5 6.0 -
Assessment Methodology
Calculation Steps:
  1. Identify Line Horse - consistent performer used as reference
  2. Calculate WFA Allowance based on age, distance, and month
  3. Apply Drag Adjustment for beaten margin
  4. Calculate Actual Weight Performance:
    Weight - Drag - WFA
  5. Compare to Line Horse to determine race rating
  6. Apply special rules (maiden caps, layoff allowance)
Key Formulas:
  • Drag Effect: Varies by distance (see Benchmarks page)
  • 1 length ≈ 1kg at 1 mile (1600m)
  • WFA Scale: Based on Admiral Rous's 1855 table
  • Rating Points: 1kg = 2 rating points