This season’s Kentucky Derby preps have come and gone. Barring defections, the top 20 spots on the Derby leaderboard are locked up, and we know which horses are likely to enter the starting gate on the first Saturday in May.Up until this point, this list had been a hybrid of one handicapper’s opinion and runners likely to make the field. Now, though, we can exclusively focus on the top 20 horses on the leaderboard.