It may have been 1 in 540 this year but the odds depend on the number of starters.
Let’s see them do it in the Preakness and Belmont. Then I’ll be impressed.
Last year’s superfecta paid only $63.41 - less than the trifecta ($202). There were fewer bets laid on the superfecta than the trifecta, and the bets that were laid were not randomly distributed.
http://helloracefans.com/pdfs/charts/2015-Kentucky-Derby.pdf
This year’s superfecta paid $542.10
http://helloracefans.com/pdfs/charts/2016-Kentucky-Derby.pdf