"As you probably know, the basic 5 ball pattern is the cascade; i.e. the same as the basic 3 ball pattern. So what makes it so much harder than 3 balls? The obvious answer is that it is faster, but that"s really only half the story. The other half is that your throws have to be much more accurate. Because there can be two balls in the same path in the air at the same time, a low throw followed by a high throw will cause two balls to come down at the same time-- disaster.
The two effects, the speed and accuracy requirements, feed off one another to make the pattern quite difficult, at first, anyway. The speed of the pattern makes it difficult to make accurate throws, and conversely, an inaccurate throw will put even greater demands on your speed. A throw to the wrong height will have one ball coming down too soon after another, while a throw which is off to the right, left, front, or back will require additional hand movement which eats up time.
All of these problems, however, are based on the interplay of the same two elements-- the speed and accuracy requirements of the 5 ball cascade."
So it requires speed, dexterity, accuracy, commitment, patience and perfect delivery .. GGWP