The favorite horse wins the Kentucky Derby approximately one-third of the time. Historically, favorites have won about 34% to 37% of the races, depending on the data source and era considered. For example, since 1908, the post-time favorite has won around 34.2% to 34.48% of the time, with 40 wins out of 116 races in one dataset, and 49 wins out of the entire history of the Derby in another
. Another source notes a 37.3% win rate for favorites over 150 editions of the race
. There have been notable streaks where favorites dominated, such as from 2013 to 2018 when the favorite won six consecutive Derbies. However, since 2018, no favorite has won, illustrating the race's unpredictability
. Despite this, betting on favorites is still considered a positive expected value play due to their relatively strong historical performance compared to other horses
. In summary, favorites win roughly one-third of the time in the Kentucky Derby, reflecting both the competitive nature of the race and the challenges in predicting the winner
