Why the average Kentucky Derby jockey is so small in height and weight

Horse racing is unique in that the human involved isn't necessarily the athlete that everyone is watching. While jockeys are more than just accessories, fans cheer for, or bet on, the horse itself.

Jockeys play a key role, however. It's no coincidence that many of the jockeys at the Kentucky Derby each year are familiar faces who return to pursue history. Some do the job better than others, even if they aren't the center of attention.

What you will notice about jockeys is that they don't necessarily come in different shapes and sizes. Jockeys tend to be small in both height and weight, and there is a reason for that.

Here's what you need to know about the size of Kentucky Derby jockeys and a look at past winners.

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Average Kentucky Derby jockey height and weight

Kentucky Derby jockeys are almost exclusively between 4'10" and 5'6", according to Horse Sport, coming out to an average of about 5'2".

While there is no height limit or requirement, there is a weight requirement as to what a horse can carry. A male horse must carry 126 pounds, while a female horse must carry 121 pounds. That, however, includes everything from the saddle to the jockey's equipment. That means jockeys typically have to weigh no more than 118 pounds, and Horse Sport notes jockeys tend to fall within the 108-118 pound range.

The weight limits have been in place at all Triple Crown races for more than a century, both to ensure fairness among competitors and to protect the horses. 

All male horses must carry 126 pounds, even if their jockey weighs 100 pounds, for example. If the total after equipment is still less than 126 pounds, a dead weight is added to make up the difference and ensure fairness between the horses. 

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Why are horse jockeys usually short?

To put it simply, bones are heavy. The taller you are, the more bone you have -- and the more you weigh, generally. Taller people tend to be heavier just because their bodies are larger, whereas shorter people tend to weigh less because there is less body to go around.

There is no height limit for jockeys, but with strict limits on the weight a horse can carry, a shorter jockey will have a much easier time coming in under the weight requirement. 

MORE: Full list of Kentucky Derby winners

Notable jockeys to win Kentucky Derby

Not every winning jockey's height and weight are publicly known, but here are the measurements for some of the recent Kentucky Derby winners:

Because of the weight of the equipment, jockeys must weigh in at well under the total weight limit of 126 pounds. No recent Kentucky Derby-winning jockey weighed more than 116 pounds, and all were 5-6 or shorter.

Managing weight becomes more difficult the taller you are, so Junior Alvarado and John Velazquez, at 5-6, likely have to follow a stricter regiment to make sure there are no close calls.