Pace parameters are a series of performance-related numbers based on the pace characteristics of a horse in a race.  Below is presented an historical review and summary of pace parameters for Kentucky Derby starters in prep races at a mile or more on dirt since 1998.  

Using linear regression (involving fractional times and lengths behind) we generate the slope and intercept of the best straight line that models the individual performance where slope is a measure of fatigue and intercept is a measure of early speed inversely related to the slope.  We use the slope and the intercept for a race to calculate a projected time at any distance.  These times include a projected ten-furlong time (10f), a projected turn time in a ten-furlong race (10fTT, the time to negotiate the distance between the six furlong and eight furlong markers) and a projected last quarter-mile time in a ten-furlong race (10fLQ).  Next, we calculate unadjusted Sartin Methodology-based Brohamer pace numbers ("Modern Pace Handicapping", by Tom Brohamer, William Morrow and Company, Inc,. New York, 1991) for the same races.  For our purposes these are limited to a 3Fr (Final Fraction) number which is the speed in feet-per-second from the six furlong call to the finish and a %E (Percent Early) number which is a relative measure of energy used through the six-furlong call.  Speed types display %E figures significantly higher than off-the-pace types, although the absolute numbers are greatly affected by the distance of a race.  We emphasize 3Fr and %E from among the various available Brohamer figures because these are directly related to a horse’s ability to save energy and to finish its races with something left in reserve.  

For each year since 1998, the starters are rank ordered according to the five pace-related parameters derived from Derby prep races at a mile or more on dirt.  They are 1) the fastest 10f; 2) the fastest 10f LQ 3) the fastest 10f TT; 4) the fastest 3Fr; and 5) the lowest %E.  Starters with the top five values in each category pass the initial screen.  In the second screen, only those passing the first screen and which have achieved a PF of -55 or better in a Derby route prep race are considered for the win.  To test the usefulness of this analysis, all qualifiers are bet across the board and in exacta combinations although this approach should not be considered a recommendation of a wagering strategy.  The results are displayed on the right side of the table.  Since 1998, this methodology has identified nine of thirteen winners as well as four exactas and two trifectas.  Since 1998, the Derby winner has been among the top 5 eight times in 3Fr, five times in %E, seven times each in 10fTT and 10fLQ, eight times in 10f,  and nine times in PF.

Because of the pace complications associated with the introduction of the all-weather surface at many tracks in recent years, beginning on 2010 the top 5 in each category was determined by adjusting the raw AWS figures to align them with the dirt figures.  This was done by calculating the average in each category for races on the two surfaces in which the horses ran first, second or third.  Then the difference in the average was added to (or subtracted from, as required) the corresponding figure for each AWS race.  For example, in 2010 the average 3Fr on dirt was 2.09 feet-per-second slower than the average 3Fr on dirt.  Therefore, 2.09 was subtracted from each horse's AWS 3Fr.  After the adjustments were made in each category, the dirt and AWS races were combined and sorted.