My gelding has always been super watch and prone to setting back. I've never had anything hold him. I'm pretty sure he'd kill himself if he couldn't get free. He's coming back from 3 months of stall rest and hand walking. It's gotten worse. Not only does he not tie, he will run backwards and buck when someone is holding him for me to saddle. THIS IS BEHAVIORAL. Any advice on breaking this habit? Is a mule tape halter stronger than a rope halter? At this point, I'm not sure I'd care if he snapped his neck. He dangerous and unapproachable when this happens. It's like both of his brain cells leave when he sets back. 

My Demon had an issue with this for a long long time. My trainer lost many halters and leads to her. But he kept tying her to the patience trailer and eventually she stopped. It wasn't pretty. I always wonder how the heck she turned out as good and sound as she has since she flipped over and pulled on her poll as much as she did. If your patience is gone and you really don't care if you have to fix another physical issue then get a triple nylon halter (or two) and make a lead/tie out of steel cable and put huge bull snaps on both ends, hook him to something unbreakable, and walk away. I had to make such a line for my stallion when he was young (he'd break loose at shows). I also had one that I had to use the rafter trick on. Make sure your rafter can't be broken, throw a rope over, tie horse high, when the horse pulls back his front legs will come off the ground and he won't be able to go further. Make sure there is plenty of room in all directions. There's no easy fix, but all three of these ways worked.

I used a tie blocker but not in the traditional way.  I looped the lead twice and got an extra long lead rope.  The horse was still able to pull back with some resitance but not enough to feel threatened because of the double wrap.  And because of the length of the lead before he got close to the end of it he was over showing out and pulling back. He just needed to do his thing. Not a behavior I encourage but he was a different kind of quirky.

I ordered a mule tape halter with a 12' lead. I'm so hoping this works. 

Can you find someone to work your horse on the ground and learn to ground tie? You may need to find someone with experience to tie his leg up and move him out until he gives in to the pressures. Tying a horse up like this will find many holes in the horse. A long time ago I had a naughty 2 year old, was awful to trim, could never get a syringe in the mouth, no vaccines ect.. In the most gentle way this cowboy tied my horse up and essentially broke her down. Let the horse fight themselves and figure it out. If that makes sense... There was a name for what they did but its been years since I have had to do that to one. I would do it again if needed. Now I will say for others who are reading this... I have a mare who randomly started setting back and she tested very high tieters for EPM. We are treating her now but if she was tied and you moved to quickly she would spook and pull and pull until she broke loose for fell backwards. This was not normal for her. Everything else was normal and great... testing came back 1:4000 for EPM.

I saw a reel on facebook about this halter the other day.  He gave it a good review on his horse, said it was very well made and worked on his horse.

https://rockinacustomleather.com/custom-order-rockin-a-sit-back-resist-leather-halter/

Blocker tie ring. I start my babies with those. I have a couple of older horses that I tie with them too. Read the instructions!  

I have one of the halters mentioned above for my mare that sets back, shes random she doens't do it all the time, but when she does she does it to get away and doens't care what she might break.  This halter has held her, I would defintly buy another and would recommed one.  There are nylon ones like this out there, but they are not made very well my mare broke them after a couple fits.  I had an old one from the early 90s I was using that was very well made, but it was so raggedy I hated having it on her away from home lol  10/10 recommend the Rocking A sit back halter!   I also use this clip when I'm tied to my trailer, have had very good luck with this combo.  https://www.valleyvet.com/ct_detail.html?pgguid=562395f7-7b04-4429-b...

If he’s only got two brain cells and both leave the chat when tied… maybe give them a safer exit ramp. Might be time for equine therapy or you therapy