Matthew has a good article about blocking. Filled with stick-figure illustration goodness, complete with eyebrows and expressions!
I take small odds with one bit:
It is impossible to know what exactly our opponents are going to do. Furthermore, it is wasted mental energy trying to figure it out. If you are constantly trying to analyze and asses the intentions of your opponent, you give him/her the opportunity to dictate the essence of the fight. You will always be a half step behind. Eventually it will catch up to you and you will get overrun.
Generally speaking I do agree with what he’s saying. If you are nothing but preoccupied with your opponent, you’ll always be behind the curve and always get smacked.
But is it impossible to know what they are going to do? And is it a total waste to try to figure it out? I would disagree with this. Most fighters will have preferences. They will move in particular ways, have particular rhythms, have favorite techniques to do. If you do pay attention, you can start to figure out what they do, what they like to do, perhaps even what they don’t do. So you throw a jab and they always pull their head back. Great. Now you can try following that left jab with a left hook: feint the jab, they pull back, land the hook.
That said, be aware that the same is going to be done to you. A good fighter is going to pay attention to what you do, you need to be aware of what you do and mix it up to keep them guessing. Matthew’s article is very good towards the physical end of blocking and not getting hit, but we cannot ignore the mental aspect of it as well. No, you cannot predict the future, you cannot know out of thin air what your opponent will do, but if you do pay attention to your opponent, you can watch for behavioral patterns and take advantage of them… it’s about as close to predicting the future as you can get.