Kentucky Derby Counterpoints: Are Favorites Less Likely to Win than in Other Races?

The “Kentucky Derby Counterpoints” series statistically challenges common assumptions about America’s most popular horse race. To read all articles in the series, go to LazyBettorUSA.com and click on the Kentucky Derby tab.

You’ll often hear the warning, “It doesn’t make sense to bet the favorite in a 20-horse field.” Maybe that’s accurate in Irish steeplechase racing, but the assertion lacks statistical support in the Kentucky Derby.

The Derby doesn’t disfavor favorites.

With 10 wins since 2000 (41% winners), this century’s Derby favorites outgalloped the 35% or so win rate of favorites in the U.S. by a healthy margin. And history shows that Derby favorites not only win at around a normal 35% rate, but they’ve produced a positive ROI for any 160-year-old horseplayer who bet all 149 post-time favorites.

If that’s the case why do we hear an annual, almost ritualistic, anti-favorite refrain from pundits and fans?

Those dead set against Derby favorites likely overemphasize results from a 20-year dry spell from 1980 through 1999. But that 20-year winless period is sandwiched between 20-year periods of 40% or higher win rates. Overall, favorites own 51 wins in 149 runnings of the Kentucky Derby. That 34% success rate mirrors the win percentage of favorites at most US tracks.

Does Size Matter?

Those positive stats don’t take field size into consideration. The prevailing assumption in the racing world is that larger field sizes result in fewer wins by Derby favorites. More competition and a greater likelihood of traffic problems should spell trouble for race-time favorites, right? Maybe those Kentucky Derby champs favored by the betting public visited the winner’s circle primarily in years with small fields.

A look at average field sizes and favorite win percentages for the past four decades suggests that assumption is incorrect:

  • 1980s: 17.1 horses; 0% winning favorites
  • 1990s: 16.7 horses; 0% winning favorites
  • 2000s: 18.7 horses; 40% winning favorites
  • 2010s: 19.7 horses; 66% winning favorites

As field sizes increased over the past 30 years, so did the favorites’ win percentage. And it’s not just the result of recent rules changes. The 1920s ranked fourth in average field size, and that decade also churned out 40% winning favorites.

Top-Level Talent Stands Out Even in Crowds

The reality is that you’ll never find 20 Grade-1-caliber three-year-olds in a given year. In a good year you might find four or five horses who can handle the rapid pace and longer distance of the Derby. If you check out the list of Gold Standard qualifiers listed in The Lazy Bettor’s Guide to the Kentucky Derby, you might be convinced that most Derby fields contain only one or two exceptionally talented beasts. So why do 15 to 20 horses pack the track in nearly every running?

Few owners of qualifying horses bypass the chance to party on racing’s most prestigious stage. Twenty spots are offered and 20 spots usually will be filled, even if fewer than five top-level horses exist. The statistics shown earlier prove that adding 15 or more subpar competitors to a race fails to increase the difficulty for clearly superior horses.

Ignoring a Derby favorite because the horse faces a dozen or more overmatched rivals instead of just the usual six or seven amounts to a lost opportunity. As shown by the stats for the 149 runnings, the difficulty level hasn’t increased all that much. In some years it hasn’t increased at all. And because field sizes are larger than typical races, favorites go off at longer odds than usual. The return-on-investment figure for a $2 Win bet on each favorite in this century proves the point:

  • ROI of favorites 2000 to 2023: +58% ($48 bet; $76 returned)

Even if you extend the timeframe back to 1970, thereby including the two decades (1980 through 1999) with no winning favorites, the ROI remains positive.

Remember to visit LazyBettorUSA.com for other articles in this series. You can also purchase my book The Lazy Bettor’s Guide to the Kentucky Derby, or get a free ebook copy by signing up for a Racetrack Super Scout (RTSS) subscription.

Addendum: Winning Favorites Since 2000

  • 2000: Fusaichi Pegasus ..$6.60 (19 horses)
  • 2004: Smarty Jones ……..$10.20 (18 horses)
  • 2007: Street Sense ……….$11.80 (20 horses)
  • 2008: Big Brown …………….$6.80 (20 horses)
  • 2014: California Chrome..$7.00 (19 horses)
  • 2015: American Pharoah..$7.80 (18 horses)
  • 2016: Nyquist ………………….$6.60 (20 horses)
  • 2017: Always Dreaming $11.40 (20 horses)
  • 2018: Justify ……………………$7.80 (20 horses)

Roger LeBlanc is the author of The Lazy Bettor’s Guide to the Kentucky Derby and The Punter’s Tale: A Bettor’s Quest for Racetrack Profits. He also published the Las Vegas adventure novel Five Against the Vig.