When you are defending against a 5-bar pass, it is a cat and mouse game. What your opponent is trying to do is (1) Simply Pass so quickly that you aren't there, or (2) do a fake to get you off your mark and pass once you've fallen for the fake (and example is the hesitation wall pass--also known as the double-pump wall pass), or (3) they use a hovering technique and "hang time" to make you commit to one hole and then they go to the other or (4) they time your defense and wait until you move off your mark and pass where you were.
If you are having problems with (1), you need to use a random jump and fake defense or some sort of shuffle. They should not be able to just blast a pass by you.It is easy for you to keep them from knowing exactly where you are going to be at any one instant. Remember--THIS IS VERY IMPORTANT--do not try to keep in the middle of their two options try to race them to the one they pass. You are in NO MANS LAND and will likely not block any pass at all. Always have you man in the position of one of their options and jump from one to another.
If you are having problems with (2), simply do not look at what the opponent is doing. Set up a defensive pattern rather than trying to block their passes.
If you are having problems with (3), then join the crowd, a well train player with a lot of hang time and good execution will get a good percentage of passes. The only real counter to this is randomly taking their favorite options and moving quickly to avoid committing. Awesome hand speed and aggressiveness is another counter. Most--lets say all--players who use hang time against their opponents don't pass perfectly every time--they flub, or pass slowly on occasion--you need the aggressiveness and hand speed on those occasions. WARNING: THIS IS A CONTROVERSIAL POSITION, BUT IT IS MY OPINION: If you do not lose the ball on a jar or reset call occasionally, you are simply not aggressive enough.
If you are having problems with (4), the problem is that your motion defense does not have any "fakes" in it. If every time you move, you change position, then the opponent simply waits until they see motion and passes where you were! The counter to this is to sometimes (often?) move your defense, but move it right back where it was. Sometimes just a twitch will cause the opponent to pass right into your men.
Other important techniques on the 5-bar defensively are to change the attitude of your men. Sometimes tip them forward, sometimes backward. The purpose is for you to adjust so the opponent will not get the ball back when they pass. Most forwards pass a similar speed each time. Some positioning of the man's foot forward or back will cause a minimum of rebounds when you do get blocks. Another way to do this is to not hold on to the handle as tightly. This allows your defense to absorb the impact and keep the ball on your men and causes the ball to stick to your 5-bar instead of going back to the opponents 5-bar. If you've got quick hands you can also try to spike their pass as an option.