It’s that time of year again! Spring has arrived, the 147th running of the Kentucky Derby Presented by Woodford Reserve is just 2 1/2 weeks away, and we’re ready to dig into some deep data to find the next winner of the run for the roses.

The Kentucky Derby is a handicapping challenge unlike any other. It’s the only race in North America where bettors must choose between 20 lightly-raced 3-year-old Thoroughbreds traveling 1 1/4 miles, a distance few (if any) have tackled in the past.

Click image to purchase shirt.

Thanks to the large field size and unpredictable nature of the horses involved, the Kentucky Derby annually ranks among the best betting races of the year, so handicappers understandably spend an inordinate amount of time analyzing the contenders.

Race replays, speed figures, and workouts all receive their share of attention, but less obvious data points come into play as well. One factor many handicappers choose to emphasize is how fast each Derby contender ran the last three-eighths of a mile of their final prep race, which usually takes place at a distance of 1 1/8 miles.

Analyzing these fractional times has become a popular tool for handicapping the Kentucky Derby, and for a good reason. Horses who finished strongly at the end of their final prep race are more likely to handle the Kentucky Derby distance than horses who tired at the end of their final prep.

Longtime turf writer Jennie Rees — an inductee in the National Museum of Racing and Hall of Fame’s Joe Hirsch Media Roll of Honor — was the first to popularize this approach to handicapping the Derby, outlining the standard by which fast finishes are judged.

Rees noted a strong finish entails sprinting the final three-eighths of a mile in :38 seconds or less and the final eighth of a mile in :13 seconds or less. However, the final three-eighths fraction alone has been a terrific indicator of a win-worthy Derby contender. Year after year, the :38-or-less rule has proved effective for identifying horses with a chance to prevail at Churchill Downs; indeed, eight of the last nine Kentucky Derby winners (and 18 of the last 23) finished the final three-eighths of a mile in their final prep race in less than :38 seconds.

Of course, finishing fractions can be affected by a variety of factors, including the speed of the racetrack and the early pace of the race — it’s easier to finish fast if you’ve gone very slow early on. But when you have a statistic that applies to 18 of the last 23 Derby winners (with two others missing the :38-or-less cutoff by 0.16 or less), you don’t ask too many questions.

So, let’s get started! Below is a chart listing the finishing times for the 2021 Kentucky Derby contenders, ranked in order of how fast they sprinted the final three-eighths of a mile of their final prep.

Before diving into the data, here are a few things to keep in mind:

1. Whenever possible, I have used data from Trakus to determine the listed times. Unlike traditional timers, which only record the fraction posted by the leader at each point in a race, Trakus provides individual times for every horse in a race.
2. For tracks where Trakus is not installed, I have calculated all times using the estimation that six lengths is equal to one second. This means a horse finishing six lengths behind the winner of a race is deemed to have run one second slower.
3. Since some tracks have a traditional timer in addition to Trakus, the times provided by Trakus can vary slightly from the times officially published in result charts. In these instances, I have used the data from Trakus.
4. Fractional times for the 1 3/16-mile Twinspires.com Louisiana Derby have been calculating by hand-timing the video replay of the race.
5. Fractional times for races held at 1 1/16 miles have been projected based on assumed finishing time for an additional sixteenth of a mile.
6. Raw times for the 1 3/16-mile UAE Derby are based on metric distances, which are slightly shorter than “equivalent” distances measured in yards. To make these times comparable with other times on the list, I have converted them to projected times based on yards.

The data for the 2021 Kentucky Derby paints an interesting picture. Three prep races — the Grade 2 Toyota Blue Grass Stakes, the Grade 1 Curlin Florida Derby Presented by Hill ‘n’ Dale Farms at Xalapa, and the Grade 2 Twinspires.com Louisiana Derby — dominate the chart, accounting for the nine fastest finishing times.

Leading the charge is the undefeated Kentucky Derby favorite Essential Quality, who finished in :36.34 to defeat Highly Motivated (:36.45) by a determined half-length in the Blue Grass. The popular Godolphin homebred looms as a formidable candidate to give Eclipse Award-winning trainer Brad Cox his first Kentucky Derby victory.

However, it should be noted that the Blue Grass unfolded at a modest early pace, making fast finishing fractions more likely. Rombauer (:36.84) and Hidden Stash (:37.36) were soundly beaten in third place and fourth place, yet they rank fourth and sixth on the chart since the Blue Grass produced fast finishing times across the board.

Known Agenda (Eclipse Sportswire)

With this in mind, we have to give Known Agenda credit for finishing in :36.59 to dominate the Florida Derby by 2 3/4 lengths. Conditioned by two-time Kentucky Derby-winning trainer Todd Pletcher, Known Agenda finished at least 0.76 seconds faster than all of his Florida Derby rivals, so it’s hard to attribute his strong closing time to favorable race dynamics or a fast track. Known Agenda simply turned in a top-notch effort.

The Louisiana Derby was also an encouraging race, with the top three finishers coming home between :37.29 and :37.82. The fastest fraction came courtesy of third-place finisher O Besos, who unleashed a determined rally up the rail to finish just two lengths behind the victorious Hot Rod Charlie. If O Besos sneaks into the field at Churchill Downs, the son of 2013 Kentucky Derby winner Orb could be a live longshot worth betting.

A few races generated unexpectedly slow finishing fractions. The Grade 1 Arkansas Derby, for example, produced four of the six slowest finishing times on the chart; even the stretch-running winner Super Stock came home in just :39.34. The Grade 1 Runhappy Santa Anita Derby also featured modest closing fractions, with decisive winner Rock Your World finishing quickest in :38.53 — slow by the standards of past Kentucky Derby winners, though the tiring nature of the Santa Anita main track these days may have played a role.

An even slower track presented itself at Aqueduct, where the Grade 2 Wood Memorial Stakes Presented by Resorts World Casino was contested. The final time of 1:54.53 (nearly six seconds slower than the Blue Grass) tells us all we need to know about the speed of the track, though the race didn’t produce the toughest field either, with Todd Pletcher’s unheralded 72.25-1 shot Bourbonic (:38.55) closing from out of the clouds to defeat stablemate Dynamic One (:39.39) by a head.

After crunching the numbers, here are my main takeaways from the chart:

• Essential Quality and Known Agenda are the key contenders for victory in the 2021 Kentucky Derby, with Highly Motivated looming as a logical candidate to finish in the top five.
• The Louisiana Derby was a solid race, with Hot Rod Charlie and O Besos in particular ranking as candidates to crack the top five at Churchill Downs.
• The Santa Anita Derby and the Arkansas Derby featured less-encouraging finishing fractions, suggesting well-regarded runners like Rock Your World, Medina Spirit, and Super Stock might be vulnerable on the first Saturday in May.

Good luck with your Kentucky Derby handicapping!