Hey all, I just had a couple of quick things to suggest, but there is already some very good information on this thread.
A hard-to-catch horse is NO fun...I have dealt with a few in my time, but luckily my new mare has been pretty good about it.
One thing though, once you TRY to catch your horse and she decides to run away or be difficult - DO NOT give up until you have caught her.
It might take hours, so go in with plenty of time, but if this horse learns just once that she can outsmart you and not be caught it can turn into a terrible long lasting habit!
After you have caught her (and you both may be exhausted and frustrated at this point) I would suggest simply taking her out of the pasture to give her some treats and groom her quickly and then put her back out (even if you had your heart set on going for a ride, I wouldn't, you both might have bad attitudes from the situation and the ride might just aggravate things). Repeat this daily as many times as it takes until things get easier.
I like to keep my horses guessing as well, by not just taking them out to work/ride them...I will take them out for grain, for time to eat grass, to be brushed, to practice loading in and out of the trailer, or just to go for a quick walk around the grounds. I think this makes it much easier to catch them all the time.
When you walk into the pasture to catch a horse, do so with purpose and don't already think in your mind that your horse is going to run away. Walk to them as matter-of-fact as possible. Talking to them to let them know you are there...if they start walking away - stop and tell them to 'whoa'. If they continue walking I will follow behind them slowly making sure that they see me whether they are looking left or right, make them think you are 'everywhere' and they might be a little more willing to give up quicker. Try not to push them into a trot. Eventually you will succeed and the more you do this the easier it should get!
Gaining trust and respect through lunging or other groundwork should be done to help you gain more control of your horse through only your presence (in the pasture), with or without the halter on, if your horse is used to listening to you and following your directions they might be more willing to be caught if that is what you are asking for.
Hope this helps, BEST of luck!
Robin and horse Deva
PEACE and LOVE to you all AND to all of your horses!!!!