Gaining ground: two long striders to watch out for at Haydock on Saturday

It is known that a horse's stride length correlates with ability, but also that stride length is affected by gradient and ground – it has been established to be shorter on all-weather surfaces, for instance.

With enough data, this complexity can be circumvented and, while we are at it, the relevant data made more obviously useful. A horse's stride length can be normalised against the average for the course and ground, simply by subtracting the latter from the former. A horse with any positive value will cover that much more ground per stride than the average.

There are a couple of good examples running on Haydock's undercard on Saturday. In the Superior Mile (2.25), there does not appear to be much disparity between Sharja Bridge and Matterhorn on their best efforts, at Doncaster and Lingfield respectively. Sharja Bridge's average stride is four inches longer, hardly enough to make a difference.

However, take into account the different surfaces and Doncaster's flatter nature and all of a sudden the relative gap is over ten inches. We are now dealing in the realms of the significant.

Sharja Bridge and Crystal King are both long striders

Sharja Bridge is less exposed and may just be finding his grade in this Group 3. He readily won a Listed race and was second in a Group 2 on his first two runs this year and has run in Group 1s the last twice. His stride length certainly implies Group-race quality.

Perhaps the most interesting strider of all at Haydock is Crystal King in the Old Borough Cup (3.35). He fairly devours the ground: his average stride length on Wolverhampton's Tapeta was recorded at 25ft3in, which is more than two feet longer than the average there.

Such a loping stride must be balanced, lest Crystal King has shown Group 1 form already (he has not but is arguably bred to, being a close relative to Crystal Ocean). He does indeed stride slowly: less than 2.10 strides per second, against an average that would be more like 2.20. Still, compared with the average he will have covered about 42ft further in the time it would take to gain a stride on him. On those terms, Crystal King would win.

A low cadence points to stamina, too, and can help on the forecast soft going when less time in contact with the ground is generally seen as a positive. A good test at 1m6f looks right up Crystal King's street.

All data courtesy of Total Performance Data, whose tracking covers more than 20 courses in the UK and North America