speed figure methodologies andrew beyer, len friedman, and jerry brown moderator: maury wolff

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Speed Figure Methodologies

Andrew Beyer, Len Friedman,

and Jerry Brown

Moderator: Maury Wolff

February 28, 2004

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“…the horses’ lines must look as reasonable as possible – but all the figures must use the same variant unless rain or freeze or a thaw changes things.”

Len Ragozin & Len FriedmanThe Odds Must Be Crazy – page 37

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A trailer-mounted track testing device (TTD), modified after the drop-hammer device used by Cheney, et al.(12) was used to measure the dynamic response of the track surface to impact loading. This machine, designed to simulate the vertical force exerted by a galloping horse, consisted of an 80 pound (36.4 kg) weight dropped in free fall from a height of 5.0 inches (12.7 cm) and is shown in Figures 1 and 2. The weight consisted of a stainless steel disc, 5 inches (12.7 cm) in diameter, bolted to a steel ram. The instrumentation for the TTD consisted of a load cell,(a) accelerometer,(b) linear variable differential transformer,(c) amplifiers,(d) power supply,(d) and recorder.(e) The force, displacement and acceleration of the weight at impact with the track surface were recorded from 10 sites for each trial.

“INTERRELATIONSHIPS BETWEEN MOISTURE CONTENT OF THE TRACK, DYNAMIC PROPERTIES OF THE TRACK AND THE LOCOMOTOR FORCES EXERTED BY GALLOPING HORSES”

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The impact force, impact resistance (deceleration at impact) and therebound energy, expressed as a percentage of the initial impact energy,were determined. The rebound energy was determined from the reboundheight which was calculated using the formula:1) H = 1/2 gt2

H = rebound height g = acceleration of gravity t = one-half of the time the weight was in the air between the initial impact and the rebound impact

The percentage of rebound energy returned was determined by theformula:2) U=mH x 100mP U = % energy returned m = mass of the weight H = rebound height P = total drop height of the weight

“INTERRELATIONSHIPS BETWEEN MOISTURE CONTENT OF THE TRACK, DYNAMIC PROPERTIES OF THE TRACK AND THE LOCOMOTOR FORCES EXERTED BY GALLOPING HORSES”

http://www.neosoft.com/~iaep/pages/protected/jissues/figpages/j1701p37f3.html

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Moisture Contentat NYRA Tracks

Source: Jerry Porcelli (NYRA Track Superintendent)

•FAST tracks at NYRA range from 4%-12% moisture content

•Moisture content will only stay constant if water is added at the same rate it’s evaporating

•Wind, temperature, humidity, sun/clouds, grandstand shadows all have an effect.

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“INTERRELATIONSHIPS BETWEEN MOISTURE CONTENT OF THE TRACK, DYNAMIC PROPERTIES OF THE TRACK AND THE LOCOMOTOR FORCES

EXERTED BY GALLOPING HORSES”

Marc H. Ratzlaff, DVM, PhD; Martha L. Hyde, PhD; David V. Hutton, PhD Rhonda A. Rathgeber, DVM, PhD; Olin K. Balch, DVM, PhD

“The dynamic properties of the track surface vary with its moisture content, composition and compaction. The moisture content of the base of the track remains relatively constant; however, the water content of the track cushion may fluctuate widely. Several studies have shown that the composition of the track surface alters the dynamic responses of the soil and that the compaction of the track surface may vary widely over different areas of the same track.”

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“INTERRELATIONSHIPS BETWEEN MOISTURE CONTENT OF THE TRACK, DYNAMIC PROPERTIES OF THE TRACK AND THE LOCOMOTOR FORCES

EXERTED BY GALLOPING HORSES”

Marc H. Ratzlaff, DVM, PhD; Martha L. Hyde, PhD; David V. Hutton, PhD Rhonda A. Rathgeber, DVM, PhD; Olin K. Balch, DVM, PhD

“Changes in moisture content of the track cushion resulted in similar changes in both the percentage of energy returned and the impact resistance of the track. Energy return and impact resistance decreased at 8% moisture and progressively increased from 8.5 to 14% moisture.”

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Email Query“I own a company called Thoro-Graph that makes high-end data for the thoroughbred industry (www.thorograph.com) . I am on a panel ("Debate: Speed Figure Methodology") at the Daily Racing Form expo in Las Vegas next month, and one of the subjects that is going to come up is whether track "speed" is constant throughout a race card -- I have long held that it is not, based on what I have observed from the times of the races (if you have made or read books about speed figures you know what I mean). Others on the panel believe the track stays the same speed barring specific weather (rain, freeze, thaw) affecting it, and use that as an assumption when making their figures.”

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Email Query“Another question that will come up is whether track speed is the same around the oval, and if not, whether the track speed relationships between the parts of the track stay constant. This is a question that comes up when assigning ratings for races run at different distances, and also for horses who race in different "paths" (we have observers who keep track of how wide horses are around the turns, and adjust the figures accordingly).I am looking for scientific backup that I can use to bolster my position...Can you send me or point me in the direction of anything I can use?Thanks for any help you can give me.”

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Email AnswersRhonda Rathgeber, PhD, DVM

Hagyard, Davidson, and McGee Equine Veterinarians

“I would agree that track times are probably not constant for the race card; this observation would be based on the fact that surfaces, namely the properties of the soil or sand, are changing throughout the day. This is dependent on the climatic conditions such as humidity, how much and what kind of maintenance is done on the track, etc…”

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Email AnswersDr. George W. Pratt Professor Emeritus MIT

Author, “Analyzing Track Characteristics”, “Racing Surfaces – A Survey of Mechanical Behavior”, etc…

“Yes, different parts of the track can differ widely and change during the card. First, consider moisture content which is very important in affecting “track speed”. That will be affected by variations in sunlight which change during an afternoon because the shaded parts of the track can change. Also, wind is very important in determining how fast the track dries. The optimum range for moisture content usually lies in the 6 to 9 percent water by weight. ”

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“Things can deteriorate quickly above 9% depending on the soil composition and fall apart at 6%, again depending in the soil composition. The water truck can change the % moisture content by about 1/2 of a percent for each pass. So, it is possible for some parts of the track to become wetter if this is greater than the loss by evaporation. Equally, some parts can lose moisture if the water truck can’t keep up with the evaporation.

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“Most if not all tracks do not monitor moisture and they just let the load go the same way over the whole route. Moisture is crucial. Just think of the difference of walking on the beach at the water’s edge and how it feels far back from the water.Compaction is another big issue. The harrow does not remove all of the compaction caused by the tractor tires and particularly by the water truck.”

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Email AnswersMichael "Mick" Peterson, Ph.D. Associate Professor

Mechanical Engineering, University of MaineCo-Author “Theoretical Effects of Different Racetrack

Materials on the Vertical Loading of the Equine Forelimb.”

“I agree with you completely. Whether the effect is large enough to change the times I do not know, but I suspect they are. The track is cut at night (I am not sure this is true at tracks other than the California tracks I work with) and harrowed between races.”

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Mechanical Engineering, University of Maine

“Between races the cushion is altered, but not the pad, and certainly not the base. The dynamic response of the track will then be impacted by the compaction of the pad during racing that is only addressed at night when the track is cut. This effect is measurable in the dynamic response of the track.”

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On whether relationships between different parts of the tracks stay constant…

“I know of several tracks where it is definitely not constant. The obvious one in the literature is a track in Minnesota (I think) that had an underground spring that was impacting the injury rate in one area of the track. This would certainly alter the speed as well.”

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“I suspect that your information regarding the performance of horses, even given the other uncontrolled variables, may be the best data available.”

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Track WateringHollywood Park

Source: Thoro-Graph Trackman

19 Nov 03 – 11:30, 12:00, 12:35, 2:10, 3:15, 3:45

4 Dec 03 – 12:00, 1:10, No more rest of day

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Track WateringSanta Anita


18 Jan 04 – 12:15, 12:40, 1:15

23 Jan 04 – 2:10, 3:20

28 Jan 04 – 12:40, 1:10, 2:15, 3:15, 4:15

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Track WateringGulfstream


22 Jan 04 – 2x btw 11:30-12:45, not at all after

23 Jan 04 – No watering all day

25 Jan 04 – 3x btw 11:00-12:30, before R5 & R8

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Factors in amount of watering NYRA tracks between races.

Source: Jerry Porcelli (NYRA Track Superintendent)

•Watches cloud cover / Wind

•Checks dew point / humidity

•Watches color of the track (changes with moisture content)

•Amount of dirt covering horses returning from the races

•Watches Time of Races

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Adjustments made at NYRA tracksSource: Jerry Porcelli (NYRA Track Superintendent)

Between Days:

•To speed up – Remove cushion, add more water

•To slow down – Add cushion, add sand, add less water_____________________________________________

•Fast tracks “sealed” in anticipation of rain between days

•Tracks “flaked” (partly sealed and harrowed) between races in anticipation of rain

speed figure methodologies andrew beyer, len friedman, and jerry brown moderator: maury wolff

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