Geek Out: Mining Derby Data
Level: Intermediate
By Jessica Chapel, Hello Race Fans Contributing Editor

Originally published on April 25, 2010

The Kentucky Derby isn’t won by wishful thinking, fond hopes, or crazy luck. Occasionally the superior horse is beaten in the Derby — as when Bimelech lost to Gallahadion. But, generally, the Kentucky Derby winner goes on from there to demonstrate still further his real greatness.
  — Colonel Matt J. Winn

The Kentucky Derby isn’t America’s oldest or richest race, but it is the race, more than any other on the American racing calendar, that everyone involved in the game wants to win. For trainers and owners, prestige comes with a Derby victory. No less comes to a bettor who picks the winner — especially a longshot winner. But don’t take that to mean you should hunt for a double-digit payoff, overlooking the obvious or the favored. As Colonel Matt J. Winn — the early 20th century Churchill Downs president credited with making the Kentucky Derby what it is today — knew well, to the best horse usually goes the roses.

The trick, of course, is figuring out who’s the best horse in a full field of 20 on the first Saturday in May. That’s not so easy — with 143 years of history to draw on and an intensive prep season, Kentucky Derby angles abound. Historical rules, pedigree insights, training trends, speed figures — there’s a way to make a case for almost every 3-year-old entered.

In 2009, Mine That Bird was a lightly regarded starter, an unknown from New Mexico with little in his past performances to suggest the Birdstone gelding was capable of an upset at 50-1. And yet, Mine That Bird, unlikely as he was, possessed a few qualities of Derby winners past. One such was that, like all but two of the 20 entered in 2009, Mine That Bird had raced as a 2-year-old (he raced so well as a 2-year-old that he was named Canada’s juvenile champion). No horse has won the Kentucky Derby without starting as a juvenile since Apollo in 1882, a fact transformed into a Derby handicapping “rule” over the years, and one of several historical guidelines based on what has (and hasn’t) been accomplished by previous Derby winners.

History, though, isn’t absolute, and long-arcing trends that seemed verities even five years ago seem less certain today. Until 2006, a layoff of more than four weeks was considered suspect. Barbaro won that year off a five-week layoff, the first horse since Needles in 1956 to do so. In 2007, Street Sense broke the “juvenile jinx,” becoming the first Breeders’ Cup winner to win the Derby. In 2008, Big Brown won off three career starts, one two-turn prep race, and from post 20 in the starting gate, smashing several rules in one tour de force performance.

But that history’s rules are broken every year doesn’t mean precedent should be disregarded. Handicapping is about assessing probability, after all, and the more exceptional a horse must be to win, the less likely it is to do so. Pay attention to where history intersects with common sense and solid handicapping: The Derby is an extreme test of fitness and readiness, requiring speed, class, and experience to win. Look for well-prepped horses who have missed no training time, and heed the gaps in a career record. Big Brown aside, adequate experience — defined as at least five career starts — is a plus for meeting the challenge of the Derby. And despite what Mine That Bird in 2009 or Giacomo in 2005 accomplished, a likely Derby winner will be proven at nine furlongs, finishing at least third (or within three lengths of the winner) at the distance as a 3-year-old.

Other factors frequently referred to when talking about Derby handicapping include:

Dosage, Experimental Free Weights, and Dual Qualifiers
A somewhat esoteric pedigree theory, Dosage in the Derby draws ardent supporters or dismissive debunkers. Based on the frequency of certain sires in a horse’s bloodline, Dosage indicates a horse’s distance potential. Broadly speaking, the lower the Dosage Index number, which is derived from the Dosage Profile, the more stamina a horse is considered to possess. Dosage is used in conjunction with the Experimental Free Handicap rankings to determine Dual Qualifiers, horses that rank within 10 pounds of the Experimental top weight and have a Dosage Index number less than 4.00. Through the 1990s, Dual Qualifiers ruled the Kentucky Derby; the theory has taken hits in the past decade, with only 2007 winner Street Sense and 2010 winner Super Saver meeting both requirements.

Tomlinson Distance Ratings
Calculated by analyzing pedigree influences, revised quarterly, and keyed to the distance of the race, Tomlinson Distance Ratings indicate the the distance potential of each horse’s breeding. A rating of 320 is considered average; ratings above 320 suggest a horse may excel at the Derby’s 10-furlong distance. Since 1998, six winners have had Tomlinson Distance Ratings better than 320: I’ll Have Another, 2012; Animal Kingdom, 2011; Barbaro, 2006; War Emblem, 2002; Fusaichi Pegasus, 2000; and Charismatic, 1999.

Final fractions
Horses that can come home fast — meaning, can demonstrate late speed by running the final three-eighths of their final 1 1/8 mile prep in less than :38 seconds — have an edge in the Derby. In 2009, every starter ran the final three-eighths of their final nine-furlong prep in less than :38 seconds, rendering this angle meaningless. In 2011, however, several starters — including Florida Derby winner Dialed In — did not manage a time better than :38 for the final three-eighths at the distance, making fractions part of the handicapping puzzle once again.

When the prep races are over, workouts remain. The moves Derby contenders make in the days leading to the Derby are closely scrutinized for evidence that a horse is in peak form, and — if it’s training at Churchill Downs — proof that it is taking to the main track surface. A bullet work at Churchill — meaning the horse’s time was the fastest at the distance that morning — indicates a readiness for the challenge ahead. Not that a bullet work is essential — what you’re looking for is a work and time that is characteristic of the horse. A Derby contender should look no worse training than it has through the prep season; it’s a bonus if the horse appears to be doing better.

Beyer Speed Figures
It used to be that when it came to the Kentucky Derby, a horse that earned a Beyer of 100+ in a prep race signaled it was one to watch. Before 2009, only Giacomo was among recent Derby winners to have not run a triple-digit Beyer in a prep race, and he was the beneficiary of a pace situation favorable to deep closers in 2005. After Mine that Bird in 2009, it wasn’t until California Chrome in 2014 that a Derby winner had again earned a triple-digit Beyer in their career before the first Saturday in May. Still, Beyer speed figures can be useful. Derby winners, and horses who finish in the money, almost always earn their best Beyers at distances of 1 1/16 mile or more. Be wary of horses who have earned their best speed figures at a mile or less, or who have not surpassed their top 2-year-old Beyer as a 3-year-old.

Part of the fun of handicapping the Kentucky Derby is the awesome potential for geeking out on stats, which just might lead you to the winner. Santa Anita oddsmaker and Xpressbet columnist Jon White looks for Derby contenders without “strikes.” In his system, nine factors are used to separate playable from bet-against horses. Kennedy, of the Kennedy’s Corridor blog, devised and refined a Derby 20/20 scheme, which relies heavily on speed figures. He explains his work in three parts: 1, 2, 3. I maintain a spreadsheet, updated annually, applying various historical criteria to each year’s field (note: this year’s updates will happen after the field for the 2018 Derby has been drawn).

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  • Nice writeup, one of the better I’ve run across.

  • “No horse has won the Kentucky Derby without starting as a juvenile”…

    Apollo did in 1882, but the point being made is still valid.

  • Yes, “since Apollo in 1882” is missing from the sentence above. It’s been added.

  • Thanks for mentioning Kennedy’s Corridor. His approach was methodical, justifiable, and just plain helpful. I visit every year to refresh my memory on his 20-point criteria. Still miss updates to this site, especially at Derby time.

  • Thanks for stopping by QQ! I miss his site, and that era of blogging (especially yours!).

  • The Two Gifts of the Century Our Oaks /Darby Double Ann the pick Three that would be Steve A Philie in the Oaks. Wise Dan in the middle and finish the Day with Cal Chrome. Print It Art Tribley

  • Hi Jessica
    I came across your article and found your Derby handicapping systems discussion interesting. I’m having trouble understanding the points total in your Railbird: Kentucky Derby Prep and Historical Criteria worksheet–and in particular your 2017 worksheet. Some fields have a numerical value, others have an “X” and some fields are blank. How did you account for these various values to come come up with your ranking of contenders listed in order of points.

    Thanks for your comment

  • Hi Joe,

    Sorry for the confusion! The points I refer to are the total points each horse earned in the Kentucky Derby prep races — the contenders are listed in order of the Kentucky Derby leaderboard:

    The numerical values in the sheet (the 2s and 1s in the nine furlong prep and final prep columns) are meaningless as math — I use them to visually distinguish between winning (2) and finishing in the money/within three lengths of the winner (1).

    In the key preps column, however, the number there (from 1-3) is the actual number of key preps a contender started in. This is a little bit of a dated column that could use some revising — “key preps” derives from some research I did about 10 years and some other work done by Kennedy’s Corridor, Kevin Martin at Colin’s Ghost, and the DRF handicappers — but it basically indicates that they started in races that generate both significant numbers of Kentucky Derby starters and more importantly, starters who win or finish in the money in the Derby. These are mostly the races you’d expect — the G1s and other major preps — and the points system has changed things up a bit.

    Hope this explanation helps. Thanks for reading!

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