Monday, 21 February 2011

Pace: the final frontier V

In this penultimate episode of Pace Wars, I establish how standard sectionals vary according to both track conditions and the distance of the race.

The final part will underscore the important definitions made during the series. 

Plus, I will belatedly reveal the name of the book I consider half-an-hour the best for those interested in the technical analysis of the sport.

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EVALUATING THOROUGHBRED SPEED: A PRIMER ON PACE (cont.)

4.9 The effect of track conditions

The predominant racing surface in European racing is grass, whereas dirt is traditionally favoured in the US. Now, synthetics are making an impact on both sides of the Atlantic.
 
Not only does the composition of these different surfaces exert an influence over the way races are run, but their condition is also highly influential.

Grass tracks can vary tremendously in moisture content. This makes grass a multi-dimensional surface as far as pace is concerned - the moisture content plays a big part in determining what type of horse is successful and which style of running is favoured.

In other words, different going conditions - from firm to soft - cause a shift in standard sectionals - the most common way that fast times are achieved over a particular course and distance.

As turf becomes soft, acceleration starts to count for less. A horse's cruising speed tends to take a lot more out of it because its stride becomes far less energy-efficient. Standard sectionals therefore describe a more marked pattern of deceleration.

But, as the surface gets really heavy, the pattern of races becomes chaotic and optimal energy use becomes blurred. Horses who lag behind through having no early speed can make big runs at the exhausted leaders.

Quantitative pace analysis on turf tracks in Europe graded soft or heavy is highly dubious, in my experience.

Dirt tracks in the US are more consistent in speed and moisture content. But there are still variations which impact the run of the race.

The most dramatic are the sloppy or muddy surfaces which follow heavy rain. Again, the finer points of energy use are now subjugated by the base need to get out of the kickback. So, early pace is heavily favoured.

But when such a track dries out to good, the slant on pace can soon change.

Synthetics are closer to turf than dirt in their influence over the shape of races. They tend to put the emphasis on a horse's finishing speed.

Indeed, the higher final-quarter velocities of some synthetic surfaces magnify the effect of trouble-in-running. A horse whose momentum is interrupted faces a costly loss of kinetic energy and has little time to recover its velocity.

Despite the broad similarities between the pace of turf races and synthetics, stallions who have proved prepotent on the grass may not prove so effective at getting high-class stock on synthetics. 

Stallions like Sadler's Wells, Galileo and Montjeu impart valuable stamina to their stock which is valuable on the undulating tracks of Europe, particularly when the going is soft, but this blue-chip endurance does not seem to play such a part on synthetic tracks.

Additionally, although calculating standard sectionals on the various synthetic surfaces is no different to the task on turf, the way races are run shows much greater variance.

Perhaps jockeys still don't have a feel for synthetics. Either way, these tracks carry particular difficulties for the analyst.

5.0 A feel for how standard sectionals vary by race distance

Consider the following sectional times from three dirt races held at the 2010 Breeders' Cup at Churchill Downs. The splits given are those individual to the winners, not for the leader.

Classic (1m 2f)  Blame          24.50     24.53     23.74     24.58     24.94
Dirt Mile (1m)   Dakota Phone             24.75     22.40     23.60     24.55
Sprint (6f)      Big Drama                                   21.34     23.21     24.50

Now look at that same data with the fastest (min) and slowest (max) quarter run by each horse:
                                                              min       max       diff
Classic (1m 2f)  Blame                       23.74     24.94     1.20
Dirt Mile (1m)   Dakota Phone            22.40     24.75     2.35
Sprint (6f)      Big Drama                    21.34     24.50     3.16

I could have employed a more technically correct method, but hopefully this slanted example makes the point: the longer the distance of a race, the more that standard sectionals converge on even pace.

In other words, sprinters tend to run much more unevenly than stayers. We have already touched on part of the reason for this on dirt - the need to get to the first bend in front. But there is a more fundamental explanation which applies in a universal setting.

5.1 Different types of energy available to the running horse

This is a wide-ranging topic which I will deal with more expansively in a future blog. Like humans, horses employ both anaerobic and aerobic respiration to meet their different energy requirements through a race.

Anaerobic energy is explosive and empowers a thoroughbred's fast-twitch muscles as it overcomes inertia in the first part of the race.

But this energy source is dirty and soon becomes limiting. As the race goes on, the horse depends on aerobic energy in the attempt to maintain its momentum or even to accelerate.

The longer the race, the higher proportion of total energy is derived aerobically. And this relatively clean source is best used by a horse's slow-twitch fibres at a steady rate. So, it is manifest over longer distances by a horse running most efficiently at even pace.

In sprints, the greater dependence on anaerobic respiration leads to a a horse running its fastest sectional times in the early stages. Typically, a sprinter bursts from the gates, soon hits top pace and decelerates thereafter.

But this pattern is far more common in sprints run in the US than Europe. Sprinters on tough, demanding turf tracks in Britain and Ireland tend not to run flat out early, particularly when the course has no bends.

For those interested in comparing thoroughbred energy use to humans, note that aerobic respiration is a more significant component for horses over all distances commonly run. There is no thoroughbred equivalent of the Olympic 100m.