Look at your horse's top 3 skills and compare them to what skills the competitions use.

Your Horse Lucian has 3 skills associated with Dressage, but that doesn't always mean he will win those comps.

Thanks for that! So should I only train for and enter into Dressage competitions for Lucian?

He's a Lusitano, which means his skills are associated with Dressage. I believe that's the Prix breed for Dressage but could be wrong.

It differs per breed and some breeds don't have skillsets that match any discipline, but a quick and easy way to see what the breed does best in is to go to the Best Horses ranking and check what the top horses get wins in. It doesn't mean your horse will always win, as they'll be competing against others with the same skillset, but it does mean their skills are targeted for that.

Crossbreds are a slightly different beast and require more consideration since their skills won't map to a purebred's, but there's a crossbreeding topic in the Events forum where you can ask. Or you can take a look at the horse's top 3 skills and see what discipline they map to.

These are three skills each competition uses, in order of importance, for future reference:

Western:
Barrel Racing ~ Speed, Stamina, Gallop
Cutting ~Stamina, Dressage, Speed
Trail Class ~ Dressage, Trot, Jumping
Reining ~ Gallop, Dressage, Stamina
Western Pleasure ~ Trot, Stamina, Dressage
Classical:
Trot ~ Trot Speed Dressage
Gallop ~ Gallop Speed Dressage
Dressage ~ Dressage, Trot, Gallop
Cross Country ~ Stamina, Dressage, Jumping
Show Jumping ~ Jumping, Dressage, Speed

thank you all so much!