Siteswap Juggling Pattern Generator and Checker

What this generator does

Handles vanilla siteswap — one throw per beat, hands alternating. Synchronous and multiplex notation (brackets and parentheses) are not read.

How to use this tool

1. Choose Check a pattern and type one, such as 441, or choose Make a pattern and set the balls, period and highest throw.
2. Press the button. The verdict, the checks and a timeline of two cycles appear.
3. Each arc on the timeline is one throw, from the beat it leaves to the beat it lands.

Understanding the controls

What to do

Check a pattern you type, or make new patterns that pass both checks.

Pattern

Throw heights in order, up to nine throws. Digits 0 to 9, then a for 10 up to f for 15.

Balls, period and highest throw

For made patterns: the number of balls, how many throws before it repeats, and the highest throw allowed. Repeats of a shorter pattern, like 3333, are skipped.

Pattern code

Leave empty for a new pattern from the browser's secure generator. With a code, the same code and settings make the same pattern again; the code is a seed, not a secret.

Worked examples

Check 441

Jugglable with 3 balls, repeating every 3 throws.

Check 432

Not jugglable: all three throws land on the same beat of the cycle; the simulation finds a beat with no ball to throw.

Code harbour: 3 balls, period 3, up to 5

414. With 4 balls, period 4, up to 7: 4552.

Common use cases

• Checking a pattern from a video or a friend before trying it
• Finding new three-ball tricks to learn
• Teaching the arithmetic behind juggling

How this generator works

A throw of height t made on beat i lands on beat i + t. The landing check uses the standard rule: a pattern is jugglable exactly when, taken around the cycle, no two throws land on the same beat; the number of balls is then the average throw. The simulation does not use that rule: it juggles the pattern beat by beat with real balls for six cycles and stops at any beat where a hand must catch two balls at once, or throw with nothing in it, or hold a ball through a 0. The page calls a pattern jugglable only when the two methods agree; over all 4,680 patterns of up to four throws with heights up to 7 they agreed every time, and 540 were valid. New patterns are made by choosing where each throw lands as a shuffle of the beats, which gives a valid pattern by construction, then keeping those with the right number of balls and highest throw.

Randomness and fairness

Made patterns come from the browser's secure generator, or a seeded one when you give a code. A code repeats a pattern while the generator is unchanged. Codes are deterministic, not cryptographic.

For how randomness is produced across the whole site, see how Generate Random works.

Assumptions this tool makes

• Vanilla, asynchronous siteswap: one throw per beat, hands alternating.
• A 2 is a held ball and a 0 an empty hand, as in standard siteswap.

Limitations and good to know

• Vanilla siteswap only; synchronous (4,4) and multiplex [33] patterns are not read.
• Says whether a pattern can be juggled in principle, not how hard it is for a person; physical difficulty is not judged.
• Up to nine throws and heights up to 15.

Common mistakes

Checking only the average

432 averages 3 but cannot be juggled: every throw lands on the same beat.

Reading 10 as two throws

Heights above 9 are letters: a is 10, b is 11.

Practical tips

• Learn 441 and 531 from the cascade: they keep three balls and mix in one higher throw.
• Odd throws cross to the other hand; even throws return to the same hand.

Privacy and your data

Patterns are checked and made in your browser. With analytics consent, a count records that a pattern was checked or made; the pattern itself and any code are never sent.