With my current horse I’m really struggling to get him to relax in the show ring. For context he is an 8 year old PRE with no show history as he was imported from spain about a year and a half ago. We are really struggling with getting him to not be so short in the neck in the show ring. At home he is able to reach into the contact and relax into the hand and the same for the warmup at the show. The minute we go into the show ring he tends to get really tense and short in the neck and doesn’t want to really reach for the contact, and with that he usually becomes too quick and running. He will do all the movements with no problem but he falls btv. This is of course the tendency of the breed, but I wasn’t for sure if anyone had any tips to start getting the same reaching to the contact feeling in the ring as we do in the warm up. We have shown all this summer and a little bit this winter and the problem in the show ring is staying pretty consistent. He is also a horse that gets nervous when he is taken away from other horses or when another horse leaves and he’s the only one in the ring, but he rides in an arena alone every day, so I’m not for sure what more I could do there. I didn’t know if anyone had any tips for this beyond just getting in the ring more.
Try him with a different rider? If you have the least tension and nerves such a sensitive horse will pick that up immediately. They are such people pleasers and try so hard. It would be interesting to see how he reacts.
Got any schooling shows around, where you can experiment a little and ride in/around the show ring the day before? Where you can confidently tell your brain “hey lets just go have some fun” and push him out into your hand a little more without caring about the score at all?
Maybe try a soundproof ear bonnet.
I first introduced my last PRE to competitions around that age. He was the type that lived with his hoof hovering over the panic button at times. He actually handled competition quite well, and I that was for a few reasons.
I took him to low key off the property rides first. No pressure. I could trailer to another barn or facility and ride in their outdoor or indoor. I then started going to clinics and riding lessons off of the farm. Then we went to competitions. So we built up to competitions and I think this horse needed that. I also acted chill at every outing. I had to. We can’t both bring the drama and nerves.
You have to keep the mentality that it’s JUST riding. It’s literally the same thing you do at home all the time.
The other thing that I think is huge, especially with this breed, is having a good relationship with the horse. This comes through groundwork and a variety of work and scenarios. PRE’s can be borderline emotional and are very people oriented. If the relationship is good with you and they trust you as their leader, they will walk through fire for you and become much more relaxed in unfamiliar or otherwise alarming situations. That level of respect and trust has to be there.
So the big things are making sure you have a secure relationship with your horse, time, practice, and remaining cool as a cucumber. You also need to ride and behave just as you do at home. Pay close attention to this. Some people ride differently (even in subtle ways) at competitions than they do at home.
If I had a horse that was tense, I might even take it back a few steps and build back up to the competition enviroment.
You could also have someone else ride him and that might tell you a few things too.
This may seem simple, but I like to do a LOT of hand-walking of my horse at the show ground both as soon as I get there, then the day of the show before my class(es). I think it helps. And this probably doesn’t help, but I sing to him, VERY quietly. 
Sorry to say this, but if he is good in the warmup at the show, and it’s in the show ring where he gets tense - it’s you. I’ve had a couple Iberians, TBs and ISH’s. These horses can be particularly sensitive to their rider’s emotional state. I would have a fabulous warmup in a busy ring, but as soon as the bell would ring my horse’s back would drop, neck would tighten, you name it. It wasn’t the horse who needed more exposure (we’d haul to my trainer’s place, clinics, show grounds) and after a few outings we’d do fine. It was me who would get performance anxiety, wanting to do well since I only showed 4-5x/ year, etc. I did a couple schooling shows where our test score wouldn’t go on our record, wasn’t spending a ton of money, and lo and behold we’d score really well. So again, if you can get the relaxed ride you want in your show warmup, I think it’s your performance tension transmitting to your horse.
I know an adult beverage helped me relax a bit 
I think sometimes being further away from the chaos of horses in the warmup ring can do it too. I know my outside leg/rein has to be a lot stronger on the side of the circle the warmup ring is on, and our mediums are better headed that way
Something else to think about - I have a friend with a not Iberian breed but sounds like your horse. Her horse gets a little nervous around several other horses (like in a warm-up) but bonds quickly and is very hesitant to leave the other horses and go into a ring alone. We’ve gone to a horse park several times where we all warm up together (even with horses her horse doesn’t “know”) but then has difficulty leaving the group warmup and riding a test by himself. We experimented and her horse did better when all of us left the warm-up to be out sight around a building.
It sure can be you, but it may not be you.
ETA: her horses are regularly worked with groundwork and she knows how to use groundwork (trained) to temper “freak out” moments.
That goes back to your relationship with the horse, in a way. Horses are herd animals, so they’re going to feel some security and comfort being around other horses. When you take them away, they may feel insecure. It’s a fairly natural instinct in these animals. If your horse feels secure and confident in you and your leadership abilities, it can be less of an issue.
I’ve dealt with herd bound horses before, including my own. They do/can get over it. There are probably some outliers or those that are more difficult about it, don’t get me wrong.
IME, if my horse and I are truly on the same page, he’s fine with our herd of 2 (him & I). Does he still find comfort with other horses and enjoy his pasturemates? Absolutely, but he’s comfortable and confident enough with me to be ok when it’s just us two.
You could practice coming and going from the warmup depending on the venue and how they’re doing warm-ups. Ride a bit, leave and walk around outside for a few minutes, come back. Just to show him that coming and going “ain’t no thang” and he’s fine leaving the others. I understand this can be disruptive and not possible at some venues though.
You could create a scenario like FiFihead mentioned. It just takes finding a few people and horses to participate though.
Love this!
Same with another rider?
What if you don’t warm up? Enter training 1 and go straight to the ring.
What if you go to a show with an on deck/holding area? Again, enter training 1 and give yourself those 6-8 minutes only.
What if you show with other horses in the ring? If you can’t find an open-age materiale class, just go do flat classes at a local show.
What if you stay overnight and take a lesson in the show ring the night before?
What if you warm-up, then get off, untack, wait an hour, and then go out for your test?
What if you start Gastrogard 5 days before the show?
Go to shows but don’t show him. Ride the warm up ring, gi for show ground walks. Make it a happy experience. Do as many times as you need to. Type of show makes no difference. I brought my OTTB to a local show a few times before he learned to enjoy it.
I tried to post this last night, but it disappeared. Working on your own mental game might help things. There are several helpful threads here on sports psychology resources. My favorite is the book Brain Training for Riders by Andrea Waldo. Techniques like visualization and breathing have helped me and my horse to (gradually) become less tense in dressage.
Good luck!
Take him Any and everywhere you can as much as you can, even if you don’t show. Just walk him around as much as you can, or pop him in the longe for a few minutes here and there through out the day , or ride him around if you’re comfortable with it. Keep doing it until it’s all no big deal. I second those who said part of the tension is you, it will help you both .
I read this as “Ideas for a Tense Horse Show” 
Lots of good advice here!
This. Rinse, wash, and repeat.
Have you tried a Magnesium supplement or Focus Equine? It might help.
Agree with others, often it’s a rider tension problem, not the horse’s problem.
I like the idea of an “adult beverage” to lessen tension! However, I’d probably forget my test…
As suggested, ride him around at shows, trail ride him, ride him in empty arenas.
hen you are comfortable with him and his predictability, ride him before a judge, as you did in an empty arena. It’s you who are the fly in the ointment.
BTDT 
A quote from this week’s Horse &Hound "I was at a show feeling like we had gone really well in the warm-up, [the horse] was switched on and with me. And then I turned down the centre line and I felt the the horse just dropped me. I said this to my Trainer… and, after a long silence, he said; “And how did the horse know the difference between one side of the white boards and the other?” This is Becky Moody, Olympic medalist in Paris, who says in the article that the comment was a light bulb moment for her. Ride them the same way, at home, in the warm up and in the arena to get the same results. Train in a way that is repeatable when in a competition. It is an interesting article.
