Official NHA Assessment

Race 4: SA DERBY 4 APRIL GRADUATION PLATE (For 1 & 2 Time Winners & Maidens)

Back to Race
Line Horse
Trajanus
Reference for assessment
Exact Matches
1 / 7
Calculated = Official
Close Matches
2 / 7
Within 2 points
Significant Diffs
4 / 7
More than 5 points
Detailed Assessment
------------------------------------------------------------------------------------------------------------------------
Pos  Horse                Age  Weight  Fin  Lengths  WFA   Pre   Race Rating  New   Adj  
------------------------------------------------------------------------------------------------------------------------
1    Chapbook             2    59.0    1    0.00     3.0   100   95           95    -5
2    Alpine Jet           2    57.0    2    3.90     3.0   97    91           91    -6
3    Trajanus             2    59.5    3    5.50     3.0   96    96           96    +0
4    African Pride        2    59.5    4    5.80     3.0   104   96           96    -8
99   Aquarius             3    54.5    99   0.00     4.5   -     83           83    +0
99   Kaalvoet             2    56.5    99   0.00     3.0   -     90           90    +0
99   Umzingeli Wenyathi   2    60.0    99   0.00     3.0   -     97           97    +0
------------------------------------------------------------------------------------------------------------------------

Horse-by-Horse Comparison

Pos Horse Pre-Rating Official New Calculated Discrepancy WFA (kg) Line Horse Calculation
1 Chapbook 100 106 95 +11 3.0 -
2 Alpine Jet 97 97 91 +6 3.0 -
3 Trajanus Line 96 96 96 ✓ Match 3.0
4 African Pride 104 103 96 +7 3.0 -
99 Aquarius - 81 83 -2 4.5 -
99 Kaalvoet - 93 90 +3 3.0 -
99 Umzingeli Wenyathi - 90 97 -7 3.0 -
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