If you are stuck at a plateau, and it happens to everyone, the best way that I have found is to vary your training session. Try training the trick differently for a while. Going for broke and attempting to make each trial a record will net you mostly failures and always a drop. That means that for each trial, there is a mistake. So, first off, try not breaking your PB record on every trial.

Second, consider training "like tricks". Certain techniques, particularly with toss juggling, relate to each other and training with one benefits many. This is probably the strongest argument for training numbers juggling in the first place, but if numbers juggling is the goal, then the reverse it also true.

If you want to master a six ball fountain, then, as I have posted many times before, three in one hand is the key. If you can get in the upwards of 100 throws with six balls, then your three in one hand is probably pretty secure. So, one thing that I would try is doing some tricks with three in one hand. Fountain, cascade, high throw with a two ball fountain underneath, under the leg, shoulder throw, reverse cascade, reverse fountain, multiplex, pirouettes, etc. are all tricks that can be done with three balls in one hand. Mix it up and begin to get a repertoire other than just standing, cycling six balls onto the floor.

Keep in mind that you need to maintain good body position while doing this - see my earlier post in this thread. Also, make sure that you work both hands, paying extra attention to the weak hand.

For me I suspect that 6 balls is my level of incompetence - I fear that will never become comfortable with 6+ balls. I still hope to learn 5 clubs one day though, but my progress with this trick has been frustratingly slow, my PB is only 34 throws. Charlie Dancey's statement that hundreds of hours of practice are necessary for a juggler of average talent are now beginning to make sense...
Gunnar

A physical ceiling is very likely. Ultimately, one is only as good as the tools that one uses. That goes for the body as well as props. If you feel like you have hit a physical limit, then you should consider some physical training geared for juggling. Weight training, yoga, pilates, Alexander Technique, martial arts, dance, etc. are all going to improve your juggling through improved flexibility, strength and relaxation. I know, none of them are as much fun to work on. After all, juggling is the be all and end all, but sometimes we have to make sacrifices for our craft!

Steven Ragatz