I have found that most horses that are difficult to catch the best thing to do is sit down in the field and ignore them or walk away,
when you do catch them, give them a treat, take them to be groomed and turn them away again so they don't associate being caught as being ridden, i will refuse to 'chase' after my horses, if they won't be caught they go hungry and i go home this in turn teaches them that playing games is a waste of time and i have found that they more often than not are really 'put out' by being ignored and feel that they are missing out on something so that the next time when they are called they will come, this will need a lot of patience from you and a lot of non-riding but it is worth the wait so that you can make everyone jealous(as i do) when they come to call without any effort on your part.
Chasing them with whips is not recommended and will do the opposite of what you want to acheive in the long run and yes there will be the odd day when they won't come of which you just walk away again, this is not allowing your horse to win the game as you are not playing the game to begin with and it doesn't take long before the horse realises this and decides that he is hungry and his first source of food is you. When he sees your back walking away he knows he has lost as my gelding did today and he hurried to the gate, whinnying after me but i just walked away so that tomorrow he will come when first called without hesitating, that may sound cruel but i will not tolerate any horse that plays games with me as i don't the time or the energy as i have other horses to see to.