The Rundown on Run-Up Distances

Suppose in a 6-furlong dirt sprint, the leader runs the opening quarter-mile in :21.70. Most people would consider this a fast pace. Now suppose in another 6-furlong dirt dash on the same racetrack and at the same class level, the pacesetter clocks an opening quarter-mile in :22.63. You might consider this pace modest and unremarkable compared with the :21.70 … but what if the two fractions actually represent similar performances, and the 0.93-second difference is entirely the result of different run-up distances? What is a run-up distance? In North America, most horse races are a bit longer than their listed distance. The run-up distance is the untimed portion before the official distance begins and the clock starts ticking. Run-up distances vary widely across various racetrack configurations, ranging from zero to a sixteenth of a mile or more. For bettors analyzing a day of racing, it's easy to overlook the effects of run-up distances on pace fractions and final times because run-up distances aren't always published in past performances. This is a mistake because the impact of varying run-up distances can be dramatic. Horses need time to accelerate to full speed after standing stationary in the starting gate. If there's no run-up distance, the acceleration phase is incorporated into the opening quarter-mile fraction, which might be seen as "slow" as a result. If there's a long run-up distance, the leaders can accelerate to full speed before the timer starts, resulting in what might be perceived as a "fast" opening fraction even if all other factors are equal. Outside North America, many races unfold with little to no run-up distance, resulting in slower pace fractions and final times than those United States horseplayers are accustomed to seeing. In the 2022 UAE Derby (G2) at Meydan Racecourse in Dubai, Kentucky-bred Summer Is Tomorrow set fractions of :24.72, :47.63, and 1:11.81 before finishing second in the about 1 1/8-mile test. A granular analysis of timing data suggested the lack of run-up slowed Summer Is Tomorrow's fractions by about two seconds. In a North American horse race with a run-up, he might have posted splits of :22.72, :45.63, and 1:09.81. Summer Is Tomorrow's speed was easy to overlook in the UAE Derby. Then, in the 2022 Kentucky Derby (G1), benefiting from a 55-foot run-up distance, Summer Is Tomorrow ran the fastest opening quarter-mile time in Derby history of :21.78. Measuring impact of run-up distances One of the most striking examples of how run-up distances can affect race times comes from Churchill Downs. In September 2025, Churchill shortened the run-up distance for its 6-furlong dirt sprints from 200 feet (approximately 0.3 furlongs) to 50 feet; then in November 2025, the distance was again reduced, down to 28 feet for a couple races before settling at 30 feet. Using data compiled by and courtesy of Equibase, we calculated the average fractional and final times across three subsets of 6-furlong dirt sprints at Churchill Downs: 103 races contested with a 200-foot run-up from Sept. 12-Dec. 1, 2024 64 races contested with a 50-foot run-up from Sept. 11-Nov. 6, 2025 46 races contested with 28-foot or 30-foot run-ups from Nov. 7-30, 2025 These datasets give us a rare opportunity to analyze the effect of different run-up distances across a single distance at one racetrack during similar racing seasons. The data is striking across the board. The average quarter-mile, half-mile, 5-furlong, and 6-furlong times all slowed with each reduction of the run-up distance. The decrease from 200 feet of run-up space down to 30 feet slowed average fractions and final times by around nine-tenths of a second. Looking beyond the averages, here's what the full datasets reveal: When the run-up was 200 feet, 79 out of 103 6-furlong dirt sprints (77%) produced a sub-:22 opening quarter-mile fraction. After the run-up shortened to 50 feet or less, only six out of 110 races (5%) featured a sub-:22 opening quarter. The impact on half-mile fractions was also strong: The 200-foot run-up distance produced 44 sub-:45 half-mile times, representing 43% of the 103 races. Only seven out of 64 races (11%) with the 50-foot run-up distance produced a sub-:45 half-mile. Once the run-up shortened to 30 feet or less, only two out of 46 races (4%) produced a sub-:45 half-mile. The slowdown continued all the way through to final times: When the run-up distance was 200 feet, 41 out of 103 races (40%) produced a final time under 1:10, including 15 (15%) under 1:09. The 50-foot run-up distance saw only 12 out of 64 races (19%) elapse in under 1:10, and only two (3%) produced sub-1:09 clockings. The 28-foot and 30-foot run-ups produced even slower results: only seven out of 46 (15%) yielded a sub-1:10 time, with the fastest time being 1:09.56. None came close to going under 1:09. In most cases, median times varied from the average times by less than one-tenth of a second. The vivid slowdowns stemming from these changes in the run-up distance teach important lessons. While it's natural to assume a :21.70 opening quarter-mile is fast, it was literally average—not special at all—when Churchill's run-up distance was 200 feet. Understanding how run-up distances influence race times can help you identify truly standout performances. Since the shortening of the 6-furlong run-up distance at Churchill, only two horses have clocked 6 furlongs in under 1:09. One was Bentornato, who dominated the Sept. 13 Louisville Thoroughbred Society Stakes in 1:08.43. One start later, Bentornato delivered a front-end victory in the Breeders' Cup Sprint (G1) at Del Mar. Horseplayers accustomed to Churchill's 200-foot run-up distance—and the multitude of sub-1:09 clockings it produced—might have underestimated Bentornato's performance. But since Bentornato had only 50 feet of run-up to work with, his Churchill time was blazing. Bettors who recognized the magnitude of his effort were unsurprised when he came back seven weeks later to win the Sprint in decisive fashion. North American horse racing is full of unusual run-up distances. One-mile dirt races at Gulfstream Park have little to no run-up. One-mile dirt races at Del Mar feature a run-up of 200 feet or more. Meanwhile, Assiniboia Downs doesn't have any run-ups at all. For players who use Equibase, the run-up distance, in feet, is listed in superscript after the distance of the race on its Premium Past Performance Programs. On Equibase results charts, the run-up is listed in one of the lines under the race fractions. Recognizing when extreme run-up configurations produce outsized effects on pace fractions and final times will make you a better handicapper. More handicapping stories by J. Keeler Johnson, as well as conversation and contests.