I'm guilty of over tightening my cinch.  I try to tell myself thats tight enough, but then I get nervous that it isn't and, tighten some more.

What I'm experiencing with both of my horses is they are yanking me coming out of the barrel. Like severe yanking. I could see if it was just one, but it's both, so clearly it's something I'm doing. I use a smart cinch on both with a leather latigo.  I'm decently fit, workout & balance with a coach 2 days a week and they still yank on my arm (some might refer to them as strong, but this hasn't always been the case.) I've switched saddle & pads still happens. I ride in a Robbie Phillips on one and a C3 on the other with a 1/2 inch 5 star on both. 

Adding that both horses have been to  Dr Ford several times since January of this year. he has injected hocks and knees on one and hocks on the other, but I'm still having this issue. Def not ruling out lameness, I have an apt tomorrow with another performance vet for a second set of eyes.  

Would love to read what you wrote / asked, but the color of your print makes that impossible.  Maybe a darker color.

So sorry! I have no idea how it got to pink, it should be fixed now. Thank you! 

Do you mean by yanking/pulling on the reins till where you kind of get pulled over their shoulder? 

No, sorry.  I mean yanking on my hand/arm  that's on the horn. When I try to get up to come out of a turn they are pulling with such GeForce it's hyper extending my arm for the first few jumps I can barely hold on without being ejected out the back door. 

 I like to beable to fit my fingers between my horse and cinch, I never really get my cinch all that tight, I ride around with my saddle snug and right befor I would make a run I would tighten up a bit more. I had a friend that would tighten up the cinch so much her horse's skin would wrinkle from the cinch being so tight, I would always cringe seeing her saddle up, LOL..But it never seem to bother her horses one bit, I guess they were used to it.

To me if your saddle is a good fit and it dont roll you really dont have to tighten up so much, unless you have a bronc of a horse, lol. I just like them snug enough to not roll when I get on and then I tighten up after I have them warmed up. Is there any gall marks are hair rubbed off your horse when you unsaddle? 

It kinda sounds like to me you are sitting up to stright coming in and out of the turns and leanning back a bit, maybe you need to lean a little more forward so you can get into a better position when your horses come out of the turn. 

Its just so hard to give you any pointers without seeing you run,  

Sounds like you may be getting behind your horse from the rate point thru the turn and getting left behind leaving barrels thus putting all the strain on your horn hand to keep you with them.  I don't think a tight cinch would cause the issue.  I know I will be slow to get up and "go with" my horses as I have been sitting doing nothing this past year.  A video would definetly help for many to actually see what / when / where you are getting left behind and offer suggestions.

You might try pushing down on the top of your saddle horn in the turn and pushing yourself down in the saddle. Some people try to pull up on the horn and actual pull themselves out further.