the rider is also critical, as a poorly fitting or badly designed saddle will disrupt the rider's balance by either pushing the rider backwards, behind the horse's center of balance, or lead to incorrect form as a way to compensate for a lack of balance in the saddle. Just as an athlete cannot perform their best if they have shoes that do not fit, even excellent riders have a difficult time riding well in a poorly balanced or ill-fitting saddle. Therefore, it is best to find a model that is comfortable and allows the rider to easily maintain the correct position. All English saddles are measured from the nailhead below the pommel to the center of the cantle. In the USA, English saddles, other than saddle seat styles, are manufactured in standard sizes for adult riders ranging from 16½ to 18 inches. Standard Saddle Seat sizes range from 19 inches to 21 inches. Most styles also manufacture proportionately smaller saddles for children. However, seat measurement is not a hard and fast way to determine if a saddle will fit a given rider. No two saddles are identical; there can be 1/4" variation between saddles of different brands with the same size designation. Length of thigh often plays a greater role in selecting a proper seat size than does rider weight or hip width. As a rough rule of thumb, sizes 16½ and below (19" for Saddle Seat) are generally for youth riders and smaller women. 17 and 17½ inch saddles are usually suitable for adult women of average size, with the 17 inch seat more suitable for shorter riders and the 17½ for those with a longer thigh (20" and 21" for Saddle Seat). 18 inch saddles are the most common size for adult men and larger women. (21" for Saddle Seat, with larger custom sizes sometimes available). Saddles are also manufactured with different flap lengths to accommodate riders of different sizes. Factors in saddle fit for a rider include the following: Pommel/Cantle height: the cantle should be slightly higher than the pommel, so the seat is not too far back (which would tip the rider backward and force the lower legs forward). Seat: the lowest part of the seat should also be the narrowest part of the saddle, the waist or twist, in order to balance the rider over the horse. When the rider is centered in the saddle,