Site-swap notation is in terms of "beats". The number is how many beats will elapse for that throw before it lands. The beats alternate hands, so any odd numb

Site-swap notation is in terms of "beats". The number is how many beats will elapse for that throw before it lands. The beats alternate hands, so any odd number means that ball is scheduled to land in the opposite hand. The standard cascade is 333, meaning each ball thrown will land three beats later, and in the opposite hand. The constraint on a useful site-swap number is this: you can't have two balls scheduled to land on the same beat, which would mean arriving at the same hand at the same time. Or more generally a ball can't land when that hand is otherwise occupied. Advanced jugglers can do that stuff physically (catch simultaneously or in an occupied hand), but it's not the purest version of juggling. More generally, advanced jugglers can do many positional and timing variations including simultaneous catches or throws, that aren't covered by the standard basic site-swap notation. There are extensions to the notation, like using parentheses around two numbers to show two throws occuring at the same time, and if the numbers are different they will land at different times.