The following table shows the class structure and associated class weights and levels used with '2008 horse races' data base.

Non-RBH classes in '2008 horse races' database
Class acronymDescriptionKg class weightClass levelFillies/mares
discount (kgs)
OPN QUOpen quality (Group)6673
OPN SPOpen sprint6563
OPN DSOpen distance6063
WEL NRWelter or transition to open class6053
F&M QUF&M quality (Group)5550
F&M NRF&M listed5540
3Y+ NR3yos+ open (no other restrictions)5953
3Y+ R23yos+ with 2 metrop wins (or equiv)5333
3Y+ R13yos+ with 1 metrop wins (or equiv)5223
3Y+ R03yos+ with 0 metrop wins (or equiv)4913
3YO QU3yo quality (Group)54-6142
3YO NR3yo open (no other restrictions)54-6132
3YO R23yo with 2 metrop wins (or equiv)45-4932
3YO R13yo with 1 metrop wins (or equiv)45-4922
3YO R03yo with 0 metrop wins (or equiv)40-5212
2YO QU2yo quality (Group)45-5520
2YO NR2yo open (no other restrictions)37-5020
2YO R22yo with 2 metrop wins (or equiv)37-5020
2YO R12yo with 1 metrop wins (or equiv)37-5020
2YO R02yo with 0 metrop wins (or equiv)37-5310
C6Class 64923
C5Class 54813
C4Class 44713
C3Class 34713
C2Class 24303
C1Class 14203
RBH Classes in '2008 horse races' database
Class acronymDescriptionClass wt
in table
Kg Class weightClass levelFillies/mares
discount (kgs)
RB1RBH-100 to 1150.6666 to 75.963
RB9RBH-90 to 990.6659.4 to 65.3453
RB8RBH-80 to 890.66553.2 to 59.18543
RBHRBH-46 to 790.6630.36 to 52.140-33

Notes to table:

  1. 3yo and 2yo classes have ranges of class weights over horses' year (from August to July the following year) specified in a format comprising: August class weight in kgms followed by a hyphen followed by the class weight in kgms for July the following year. The difference between lower and upper bounds of each range, rounded to nearest 0.25kg, is spread evenly month-by-month across the year and added to August value.
  2. The upper end of the 2YO R0 range is higher than that for 2YO R1 and 2YO R2 classes perhaps reflecting the quality spread of horses starting racing as 2yos.
  3. 'Kg class weights' associated with the RBH class acronyms shown are determined during analysis of races by multiplying the rating figures for the individual RBH classes (eg '75' for RB75) by the corresponding, necessarily relatively small, 'class weight in table' figure (the user's figure in My HorseRaces' Class Weight table).
  4. Similarly, class levels associated with these class acronyms starting with 'RB' are based solely on the associated RBH ratings (and not like other classes on the levels specified in the table):