I think it quite likely that today's 3.15 Doncaster will prove useful as a focus for considering ability ratings.
If we take VDW's basic rating - total win prize money on flat or NH as appropriate, divided by races won - we get the following ratings for the 3.15:
343 - Advanced
136 - Head Of Steam
112 - Colonel Mak
106 - Cheveton
-------------------
090 - Nasri
086 - Grissom
072 - Jonny Mudball, Shropshire
068 - Ancient Cross
064 - Secret Witness
058 - Khubala
057 - Fitz Flyer, Prodigality
055 - Trade Secret
053 - Gatepost, West Leake Diman
045 - Thunderball
044 - Farlow
033 - Vito Volterra
The race itself is a class 104, so it follows that the top four are well able to win a race of today's class, as on average the class of the races they have each won is higher than 104.
In addition, several horses with ability ratings below 104 have won one or more races of class 104 or higher, namely:
Ancient Cross (highest class win a 130)
Grissom (218)
Nasri (125)
Secret Witness (130)
so it would have to be accepted that, on VDW's measure of class and ability, these four could also all in principle win today.
Given VDW's advice about ability ratings - "always mark off the four highest ability ratings", and his practice - not going below 5th highest with any of the winners he claimed, if one was assessing the 3.15 from a VDW main method perspective one wouldn't necessarily limit oneself to the top five from which to find the class/form horse, but if the class/form horse, once identified, was ranked 6th or lower on ability, he would be a selection but not a bet.
What to me is interesting about VDW's approach re ability is that it tends to leave out potential. For example, on the above reasoning from the evidence, VDW would not consider backing either Khubala or Prodigality, even if one of them turned out to be the VDW main method class/form horse. And indeed neither horse has won a race of today's class. But both are young (3 and 4 respectively) and have come very close to winning races of today's class - Khubala having won a class 100 and been a close second in a class 124, Prodigality having finished a close second in class 100 and 124 races. Irrespective of what happens in today's race, if they stay fit over the next year or two it is difficult not to see both horses winning races of over class 100.
We may well find in about forty minutes (I am typing this at about 2.40pm) that in this case VDW is proven correct, but I certainly won't be shocked if one of the younger, less exposed horses shows sufficient improvement to win. Over the season enough do so to make it necessary, in my view, to allow for realistic improvement when assessing ability.
