We're getting right down to the nitty gritty of Derby Handicapping. People are settling on their selections and in a race with 20 entrants you realistically have a short list of about 5 horses. It's really no different from any other race you handicap. Most races have a field that is about half the size so obviously it's easier to narrow it down to 2 or 3 horses instead of 4 or 5.
How do you boil down the short list to come up with just one, your official Derby pick? Most handicappers get picky and are forced to use the slightest excuse to drop one of their main contenders. After all there is plenty to like and little to choose between your contenders, that's why they made the short list.
A popular angle that some people use in these situations is experience over the track. Every track has its subtleties and knowing if a horse likes Churchill Downs is an added bonus right? Surprisingly the numbers suggest that this isn't really true. Over the past 13 runnings 32 horses have entered the Derby with a prior win at Churchill Downs. Only Street Sense and Denis of Cork managed to hit the frame. A lot of well backed horses have sucked some money over this angle.
Horses that have run at Churchill Downs but have failed to win are actually a much better 31-3-1-2. In many cases those horses actually ran badly at Churchill in their only attempt.
As always you can make of this data whatever you will but for me this information leads me to resist using prior track experience as a refining angle. A good race, a bad race or even no race at Churchill Downs doesn't seem to make a big difference.