Though it consistently produces the most logical results of the Triple Crown races (due to a smaller field than the Derby and a more common distance than the Belmont), the Preakness has still provided its share of upsets.
The highest priced winner in the race’s history is Master Derby, who triumphed at odds of 23-1 in 1975. Second on the list is Coventry, who was sent off at 22-1 when he captured the 1925 edition. While both were clearly unexpected, neither would register among the top 5 highest-priced winners of the Derby or the Belmont.
In recent years, horses like Oxbow (2013, 15-1) and Shackleford (2011, 12-1) have produced mild upsets, however a perusal of past results makes it clear that the Preakness is not a race conducive to huge longshots.