The field for the Kentucky Derby on May 7 at Churchill Downs is limited to 20 runners, and when more than 20 enter, preference is given to horses who earned the most points in 34 designated prep races from September through the Arkansas Derby on April 16.
One interesting aspect of the entry process on May 4, though, is that Churchill Downs allows up to four also-eligibles, so even for those on the outside looking in, they could get an extra 48 hours to draw into the race.
Here's what would happen if entries were taken today:
The 20 horses in the race would draw for posts 1 through 20, with a traditional, double-blind draw. A sheet of paper with each horse's name is pulled one at a time, and then a numbered pill is taken one at a time from a plastic, opaque bottle. Last year, for example, American Pharoah's sheet was pulled when the number 18 pill came out of the bottle. So, American Pharoah was number 18.
That's the way it will be done on May 4 for posts 1 through 20. The horses ranked 21st through 24th on the points list -- currently, in order, Fellowship, Adventist, Laoban, and Dazzling Gem -- would be assigned numbers 21 through 24, and they'd only get into the race, in that order, if horses among the original 20 drop out before scratch time, which is 9 am Eastern on May 6. If one horse from the top 20 drops out, Fellowship would get in. If two, so too Adventist. And so forth.
So even if a horse doesn't make it into the top 20 by entry day May 4, he still has 48 hours to draw in.
After that, the field is set. Even if there's a late scratch on Derby morning, it's too late.