I was curious if the back cinch helps with slipping. I have a huge issue of the saddle slipping because my horse is round,built like a tank,and no withers. The saddle fits her it's just since she has no withers it makes it harder for me to get on. I was able to get on twice today without and help.I'm getting better. Just wanting to know if that will help..especially when galloping? I usually feel it slipping in the back when running which causes the whole saddle slipping so I have to make sure I straighten it out as I am in a gallop. It's not that big of deal. I can deal with it...anyways if it helps let me know!
I have the exact same problem with my gelding Pro. His back is literally FLAT. It drives me absolutely crazy. I've tried sooo many different saddles and Pads none make even a slight difference. The ones with FQHB's and Extra wide trees only make the problem worse for Pro. A breast collar helps quite a bit. I use a collar, back cinch, my 5 star saddle pad, and of course a front cinch (roper works well). It seems to work the best....Also make sure your front cinch is pretty snug (I always have to tighten it just before we run, then I loosen it after) - more then on other horses.
This type of breast collar works best with Pro (it has the two straps on the end instead of just one). It really helps secure you saddle.