Does your horse always seem to be less co-operative when you are in a hurry?
Do you sometimes think he is being difficult on purpose, just to annoy you?
 catch a horse
Firstly it is unlikely that your horse is being deliberately difficult - Every horse has his own personal space and you must take this into account when catching him.

When you are in a rush, you probably march up to your horse brandishing his head collar in front of you, calling his name loudly - He will interpret this as aggressive behaviour and the action of a predator, you need the permission of your horse to enter his personal space.
You stand a much better chance of catching your horse if you allow him to invite you in to his personal space. Take your time and walk gently and quietly towards your horse, giving him time to notice you and be aware of your intentions. Try and keep your body and mannerisms relaxed and allow him to sniff you and make the initial contact before you try and put his head collar on.
Catching your horse should be a relaxed and forth coming exercise - after all he is a flight animal and will run from something he is not comfortable with.
Try and catch your horse every day even if you don't plan to ride him. Brining him out of the field to groom or feed him, both of which are activities he enjoys, will help him associate his head collar with a pleasurable experience.

If you want to create a problem catching a horse, visit him only when you want something, and then put tension on his lead rope whenever you have a halter on him. Start doing the opposite and your horse will stop thinking “Oh no” when he sees you coming and start thinking “Oh good!”  I don't need to run.
 Read more great articles on helping you understand your horses' behaviour