Reinvention seems unavoidable for almost every product. In an era built on upgrades, it’s sensible to strive toward improvement.

Running shoes, for example, have showcased record-breaking quality in recent years. The Nike ZoomX Vaporfly Next%, a shoe by Nike, has been associated with a new record set for a women’s marathon. So why is it that the horseshoe has seen relatively little advancement?

As a symbol of luck, this equine hoofwear hasn’t been too lucky in terms of progress, and Dr. Simon Curtis, a New Market, England farrier of 47 years seems to know why this might be, according to The Telegraph. He offers the example of the horseshoe’s shift from being heated in a forge and shaped at an anvil to being factory made.

“It is a bit like buying a suit from M&S,” says the International Horseshoeing Hall of Fame member. “For the most part, it does well and is very good but if you want the very best you have to go to Savile Row.”

The minor changes that the horseshoe has seen might be a testament to how perfect the design has been since its origin. When some of the only progress includes switching from steel to aluminum and offering designs that are more suitable for the individual horse, it says a lot about how accurately the product does its job. There isn’t much more that can be done when you offer a horse its glass slipper.

Further improvements such as data-relaying inserts have been attempted, but for most horse owners it appears to be a tool of intrigue rather than progress. Perhaps the best way to understand this stagnant growth of horseshoes is to better understand the structure of the hoof itself, and how the two have come to be such an ideal fit. In Curtis’ book The Hoof of the Horse, he documents 10 years of research about the hoof’s development, health, and more. Through this exploration, he provides exactly what is needed to comprehend the horseshoe’s lack of change—a “deeper knowledge of the hoof than has ever been possible before.”