of course they know what you are going to do if its a set pattern...that is exactly why it is SET in the first place.
in tkd i always used to jam them with a side kick when they move in, timing is important in doing this, but it works most of the time, because you intercept their movement and they can't move out of the way fast enough, of course you must also be at a distance to facilitate it. energy can only move in one direction at a time so once they commit to moving in on you, they cannot change it easily or quickly.
if by sparring drills you are referring to one or three step sparring (i am assuming this is so)...i dont think they were meant to teach all out sparring, or "non set" sparring, or you would not need to do free sparring, but you do so let that be your teacher. one and three step sparring show ideal timing, when and where you would block ideally...that does not mean you can always do it (usually not actually in my opinion)...again i think they were meant more as a basic introduction to sparring, timing, distancing, etc etc...where you will learn the most about sparring is in actuall sparring.