Black Caviar, not that fast? That’s a seemingly bizarre statement to make about a sprinter who has just notched her 18th straight win, and was officially rated the best older horse in the World last year. Of course, in making that statement, we are actually indulging in some hyperbole as prelude to making some points about speed in the racehorse, whether pure speed is what sets Black Caviar apart, and how that all relates to the Two-Year-Old in Training Sales (which are just over the horizon if you live in the Northern Hemisphere).
This line of thinking was initiated by an intriguing article that appeared on the Australian Courier Mail web site . The article focuses in some of the in-race fractions that Black Caviar has set, and reveal that she is delivering virtually unprecedented bursts of speed, to settle the race, and that on occasion she’s been able to sustain that kind of finish for up to three furlongs (600m). The article continues by crediting much of that ability to Black Caviar’s in-race stride length, which is reported as being just over 27 ft. (8.33m), which means that she is taking 24 strides per furlong (200m) when the average horse might be taking as many as 30 strides to cover the distance. We are not sure that we completely in agreement with the suggestion of a 27ft stride. If you slow down the video and count the strides between the 400m and the 200m (which she does in 10.6 seconds), she does that in 25 strides which works out at 8m or 26.24ft.
What first struck us when we read the article, is that when broken down, the sectionals don’t show that Black Caviar’s peak speed in a race – when taken in isolation – is freakishly fast. The quickest furlong (200m) split that is given shows her covering the distance in 10.27 seconds, that’s fast, but no faster than than is frequently found in a Two-Year-Old in Training Sale (for a quick comparison, in the first under-tack show at the 2011 OBS March Two-Year-Old in Training Sale, more than 30 youngsters ran a furlong at least as quickly). There would be little doubt that any horse in the field of talented speedsters that Black Caviar dispatched in the VRC Newmarket Stakes (the race from the fraction was taken) could turn in that type of furlong any day of the week. What is devastating, and almost unique is that Black Caviar can produce that type of burst off an already fast pace. So what is setting her apart is not necessarily here all out top speed – she may not necessarily even have the fastest absolute top-speed in the field – but her ability to produce that speed in the context of a six furlong (1200m) race.
It’s a somewhat similar story with the stride length. A stride length in the 26-27ft range is not that unusual in itself, especially in a turf sprinter, in fact it would be fairly typical of the type of horse that is found at the business end of good graded/group stakes competition. Going back to the Black Caviar and the Newmarket, in a breeze-up you would probably find that the entire field had a stride in the 25-27ft range. We would suggest that, as far as stride-length is concerned, what is setting Black Caviar apart is not the length of her stride, but firstly the fact that she can maintain that near-maximal stride-length for a longer duration that her rivals, and second that she is also demonstrating a faster stride frequency, she turns over that 26ft stride more frequently than other horses in the field with similar stride lengths.
Consideration of the above has some interesting implications for the way we think about speed, and also the way we select stock from the Two-Year-Old in Training Sales. To start with, it’s clear from the fact that Black Caviar’s peak in-race velocity is no quicker than a smart juvenile doing a breeze, that when we consider equine sprint racing – which in the U.S. at graded level means races between 6-8 furlongs (1200m – 1600m) – we are not talking about the all out speed that characterizes a short course Quarter Horse race, or a human 100m or 200m contest. So even at the shorter end of the spectrum, top-class thoroughbred races are decided not by pure speed, but by who can deliver the most speed at the appropriate time. That’s what makes Black Caviar an invincible Champion, not her flat out speed, or maximal stride-length, but the speed and stride-length she can maintain at the business end of a contest over 1200-1400m.
That type of ability isn’t derived from a single factor, such as a variant of the MSTN gene that regulates myostatin, the so-called “Speed Gene.” It would be very suprising if virtually the entire field of sprint specialists that Black Caviar accounted for in the Newmarket were not all sprinting genotypes. Instead, Black Caviar’s remarkable powers would be a function of many factors involving her phenotype (for example biomechanics, cardio function, muscle pennation angle), but also her genotype (including, but not limited too, various energy pathways, ability to deal with lactate, and neurological signaling). Now, when we come to a Two-Year-Old in Training Sale, two of the factors that commonly weigh heavily are the time taken for a breeze, generally over a furlong or a quarter, and stride-length. While speed over a short distance, and a long stride (as long as it is not a long, slow stride!) are desirable characteristics, as we see from the example of Black Caviar, they are not necessarily ones that will separate a horse from it’s peers. There is no doubt that appreciation of the above factors has improved greatly over the years, with intense scrutiny being paid to gallop-out times as well as the published breezes, and those who measure stride coming out with some very sophisticated ways of going far beyond stride-length in assessing biomechanical efficiency. Measurement of cardio function has also become a very important part of the process of determining athletic potential.
Important as they are what none of these provide is information regarding the genotype of a young Thoroughbred. Until a couple of years ago, the genotype of an individual with regard to athletic potential – a decisive factor in determining performance – was an area that could not be tested. That, however, has changed over the last couple of years. Advances in genetics mean that it has been possible to create a predictive test for a panel of genetic variants that have a significant impact on performance, in terms of both class and distance, that requires nothing more than a handful of tail-hairs and a few hours to work out.