What is a significant indicator that a saddle fits a rider well?

A significant indicator of whether a saddle fits a rider well is that the rider can maintain balance and comfort while riding. When a saddle fits properly, it allows the rider to sit in an optimal position, distributing their weight evenly and maintaining a secure seat. This balance is crucial for effective communication with the horse and for riding safely and skillfully. A comfortable fit also means that the rider can concentrate on their riding aids and techniques rather than being distracted by discomfort or instability.

Focusing on the other options, the heaviness of the saddle when lifting does not correlate with its fit for the rider, as a saddle's weight is more about material and construction than rider fit. The position of the saddle being high is not an accurate indication of proper fit; instead, it should be level to the horse's back for correct balance and effectiveness. Lastly, while the adjustability of a saddle can be beneficial for achieving a proper fit, it does not inherently guarantee that the saddle fits well. A well-fitting saddle will ensure the rider's comfort and balance, which is the key indicator.