Some saddle makers believe if the front angle fits your horse, then
the entire saddle fits. This is not true. The angles in the middle
and back of the saddle tree bars, and the amount of rock in the
bars can make a big difference. And angles change once the horse moves.
If a saddle maker or sales person tells you a specific size will
fit based only on the type or breed of horse, they are totally guessing.
Some saddles are actually fitted too narrow, which induces discomfort (by concentrating
all the weight onto the front and/or rear points of a saddle) in order
to encourage the horse to perform a specific animated action. Unfortunately,
these designs have been accepted by sub-cultures who value looks more
than the long term health of their horses. Many “gaited”
saddles are in this category.
Some saddle makers believe in ‘flexible’ trees that
move with the horse. Most of these still contain
immovable or hard structures for the pommel and cantle and are in
effect only 'barless'. Saddles are meant to distribute the rider’s
weight evenly and quietly over the horse's weight bearing surface.
When parts of the saddle flex, weight is concentrated in the hard
surfaces that remain.
Further, flex tree saddles usually result in an unbalanced rider and consequently a very sore horse, and tissue damage
e. Most saddle makers and fitters only put what they think is the best choice of tree on the hose. They never offer options. If you don't compare multiple options, then you can't know if another tree or angle of saddle would have felt better to the horse.
Every horse and rider has their own physical history that affects what will allow them to comfortably work more effectively. Sometimes what looks like it should work, is not what feels the best to this horse and rider pair. (We have not even begun to discuss how greatly the saddle design affects the rider!) The best option cannot be determined without riding in at least three choices, preferably a lot more.
But Choice takes Time (to figure it out by riding in multiple saddles back-to-back) and Money (to stock more options). And why do that if people will just accept the first saddle the maker or fitter says is "The One".
The Bottom Line
have to educate yourself and match the right saddle/tree to your
horse's back. The only way to know for sure if it fits is
to put it on your horse and check - first on the ground, then while riding. It helps to see
and feel good fit and bad fit, and to learn to see what the horse
is telling you about it. Start by reading the Ten
Elements of Fit. And seek out an experienced saddle fitter for
help with this.