The other day I watched a film of a very fast farm pup. The pup showed a brilliant burst of speed in around 2 turns (approx 3/16ths), after breaking belatedly from the backscretch. I noticed that as the greyhound raced around the turn and into the stretch, she failed to change her lead as she straightened, after completing the turn.
I mentioned it, and I got the feeling that no one seemed to know what I was talking about, or cared too much....and its pretty important that one understand the basics of the double suspension gallop of a racing greyhound, and why greyhounds change their "lead".
First of all, in double suspension, unlike the galloping gait of a hosre, the greyhound achieves "lift" in the extended phase of stride as well as in the flexion phase. The horse's 4 hooves are only off the ground, simultaneously, in the flexed----or closed----stride phase. the greyound, however, extends forward with such athleticism and velocity, that he literally becomes airborne at the point of full rearward and forward extension.
Since greyhound (and horse) tracks have counter-clockwise turns, the racer has to adjust his stride into the turn, so that his right side is the weight bearing side.
To actually race around a counterclockwise turn, a greyhound must be on its "left lead".....which is the terminology for a sequence of footfalls through the stride, that goes like this (aerial view)
What that means, is that the left rear foot strikes the ground first (hence the "left lead), the right rear falls 2nd, the right fore falls 3rd, and the left fore falls 4th......
Now, some greyhounds break on their left lead, and some break on their right lead. But they all must run the turns on their left lead, to equalize the effects of centrifugal force, and to bear their body weight as they turn.
The greyhounds footfall sequence on the right lead looks like this....
Now, when a greyhound is running the turn---on its left lead----its right side naturally becomes more affected by fatigue....so if the greyhound switches to its right lead, as soon as it comes off the trun, it will usually allow itself to continue at a similar or even slightly increased stride frequency, perhaps even with a bit more power.
If it fails to switch its lead, the exponential effects of fatigue will assert themselves, and the greyhound will----sooner or later-----suffer a decrease in the the scope and the power/frequency , and thus the efficiency of its stride......it will begin to lose velocity, or "lose its action"....which can happen even if the dog changes leads, but will happen sooner if it doesn't.
Often, greyhounds who "blow the turn"----that is, suddenly swing extremely (and often unexpectedly and dangerously) wide from an inside or mid track line, do so because they are unsighted of the lure in traffic, and cannot judge where the first turn is, and are late changing their lead from right to left.....and the dog cannot turn left while on its right lead , so it runs straight, as the lure turns, until it finally makes its lead change.....of course, there are some dogs who prefer to run wide, and do so, irrespective of where they are boxed.
Additionally, we can tell whether a greyhound breaks on its right or left lead, if we watch closely.
This is important to know, when deciding on whether or not you wish to enter a greyhound in a 3/8th race, where the a turn presents itself immediately after the break. Greyhounds who begin on their left lead have a distinct advantage in this race configuration.....as they do not have to make the split second change from right lead to left lead to negotiate the turn after only a few strides. Many great 3/8ths racers are greyhounds who prefer to break on their left lead.
Likewise, sprinters who refuse to change their lead from the far turn into the homestretch, though they might be very "strong"" sprinters, are not likely to thrive in 3/8ths races, where they will have to run 110 yards further, on the wrong lead.
A smart trainer can steal a lot of 3/8ths races with sprinters if he understands and applies basic stride fundamentals....and can often predict when greyhounds are going to be "short" in sprints, because they don't change their lead when coming into the homestretch after the 4th turn.