How Juggling Works


Juggling involves the repeated tossing and catching of three or more objects. Find out how juggling works and learn how to juggle multiple objects.
Juggling involves the repeated tossing and catching of three or more objects. Find out how juggling works and learn how to juggle multiple objects.
Photo courtesy stock.xchng

The art of juggling has entertained audiences and challenged jugglers for thousands of years. Although it was once confined to vaudeville and music halls, today you can watch juggling competitions on television and see jugglers keep seemingly endless numbers of objects aloft. The term is not exclusive to objects thrown in the air, though. Everything from plate spinning to playing with devil sticks falls under the umbrella of juggling. In fact, you could define juggling as using feats of dexterity to manipulate one or more objects.

Most people tend to think of toss juggling when they hear the word "juggle." Toss juggling means the performer is throwing and catching at least one object more than the number of hands he's using. In other words, you can juggle two objects with one hand, but if you use both hands to juggle two objects, you're really just playing catch with yourself.

In this article, we'll primarily concentrate on toss juggling. We'll have a quick lesson on how to juggle three objects and look at the patterns almost all juggling sequences are based upon. We'll also look into the science behind juggling, including a glimpse into the surprisingly complex mathematical theories behind throwing stuff into the air and not letting it drop.

How to Juggle

So you want to learn how to fling machetes around while balancing on a board that's on fire. Where do you start? Well, unless you want a trip to the emergency room, the best place to start is with harmless juggling balls. This section will help you learn the basic three-ball cascade pattern of toss juggling.

When most people try to learn to juggle with no instruction, they tend to start with two balls -- one in each hand. They begin by tossing the first ball in an arc from one hand to the other (normally from their dominant hand to their other hand). Then, as the ball reaches its zenith, they hand off the second ball to the hand that made the toss and then catch the tossed ball. Since they are using two hands to move two objects around, this isn't really toss juggling. It is, however, the basis for the shower pattern, which uses three or more objects. The shower pattern is actually a relatively challenging pattern, particularly for beginners.

Much easier than the shower pattern is the cascade pattern. Cascade patterns require you to toss a ball in an arc from one hand to the other and back again. The arc of each toss goes inside the path of descent of the previous toss. When you juggle, your hands move in a figure-eight motion. Your right hand moves clockwise and your left hand moves counterclockwise in alternating tosses. You can think of it as making scooping motions toward the center of your body. It sounds complicated, but it's actually quite simple.

To begin, get three balls (or bean bags, as they drop dead and you'll be dropping them a lot). All three should be the same size and weight. Put two of them down for now. Place your feet about shoulder width apart, and hold your arms bent at a natural and comfortable angle. Toss the ball from one hand to the other and back again. You want your arcs to peak a little higher than eye level. Consistency is important -- you need the height to be the same whether you're throwing from your right or left hand.

Once you have a feel for the toss, it's time to pick up a second ball. Hold one ball in each hand. Toss the ball in your dominant hand in an arc just as you've been practicing. As it peaks, toss the second ball in an arc that goes up inside the descending ball's path. Avoid handing the second ball to your dominant hand or throwing both balls into the air at the same time. You should be able to count the two tosses distinctly.

You won't be able to create a steady, smooth pattern using only two balls, so don't worry if it feels a little awkward. Once you feel comfortable starting with your dominant hand, it's time to switch and start with your other hand for a while. Nothing else should change as long as your tosses are consistent. If you find yourself throwing both balls at the same time, you might want to designate your tosses by saying "one, two" or "left, right."

Throwing in a Third Ball

Three-ball cascade
Three-ball cascade
Photo courtesy of stock.xchng

When you've mastered the crisscross pattern of tosses, it's time to add the third ball. Hold two balls in your dominant hand. It might feel unwieldy at first, but you'll get used to it quickly . Always start with the hand that has the most props in it first. Toss the first ball to your other hand, just as you've been practicing. Again, once the first ball peaks, toss the ball from your other hand. As that ball peaks, toss the third ball from your dominant hand to your other hand. Congratulations, you've just juggled a flash of three balls!

Of course, not everyone catches on that quickly. Some people find it fiendishly difficult to make that third toss. There are a couple of ways to try to­ get around this. One is to stop worrying about making catches -- just make the tosses. Again, it might help to count your tosses out loud. Another good remedy is to put two balls in your non-dominant hand. It might make the first toss a little unpredictable, but many people find that switching off can help them break the habit of holding on to the third ball.

Maintaining a cascade is pretty easy once you get the hang of it. It's just a series of tosses from one hand to the other, and once you build up the muscle memory needed to make consistent tosses, it's a snap. The only tricky bit is that you already have an object in the air while you're doing it. The most common issue with jugglers who have just learned the cascade is chasing the objects. Many people find that each throw goes a little farther out from the body, requiring them to chase the balls. Jugglers will tell you to stand in front of a wall when you juggle so that you can't move forward. With enough practice, you should soon be able to juggle while standing still.

Three-ball Juggling Variations

Bean bags are suggested to learn to juggle.
Bean bags are suggested to learn to juggle.
Photo used in the public domain

The cascade provides the basis for hundreds of three-ball juggling tricks and variations. The most common variation is the reverse cascade. In a reverse cascade, ascending balls go over the arcs of the descending balls instead of under them. Your hands move in the opposite direction they would for a normal cascade -- counterclockwise for your right hand and clockwise for your left. In other words, instead of scooping your hands inward, you scoop them outward. Most new jugglers find the pattern a little more challenging and less natural than the basic cascade.

Another variation is the half shower. In a half shower, the juggler tosses the balls from one hand in a reverse cascade pattern (scooping outwards) and uses a regular cascade pattern with the other hand (scooping inwards). The pattern can go clockwise or counterclockwise, and, it's quite easy to shift from one to the other with a little practice.

Tennis is another variation that is between the reverse cascade and the normal cascade. In tennis, the juggler tosses one ball in a reverse cascade while tossing the other two balls in a regular cascade pattern. The ball in the reverse cascade passes over the other two balls, much like a ball over the net in a tennis match.

The shower is one of the more difficult basic variations. A shower pattern is circular -- one hand throws the balls in an arc while the other catches and feeds them back to the first hand. Some jugglers use a very low, fast toss from the catching hand to the tossing hand, while others actually put the ball into the tossing hand. Most people naturally gravitate to this pattern when practicing with two balls, but once you get up to three it becomes pretty challenging.

Other variations require the juggler to cross his arms and make throws under the other arm. Doing this once is simple, but there are complex patterns that require jugglers to constantly cross and uncross their arms while keeping a juggling pattern going. One such pattern is called Mills Mess, invented by Steve Mills. In this pattern, the juggler's arms do all the crossing -- the balls actually never cross paths at all. There are many other variations of three-ball routines with equally interesting names. Burke's Barrage and Rubenstein's Revenge are two other well-known variations.

You can even juggle balls upside down. Bounce juggling is just what it sounds like. Instead of tossing balls up into the air, you bounce them against the ground and catch them on the rebound. Jugglers can use a lift bounce by lightly tossing each ball upward and letting it fall to the ground, or they can use a force bounce by throwing the ball at the ground. Force bouncing is faster but gives jugglers more control and accuracy.

Common tricks with three-ball juggling include tossing balls behind the back or under the leg as well as bouncing a ball off a body part like the knee, foot or forehead. You might also see a juggler catch objects using a fast, downward grabbing motion, called clawing. Or, he might move an object in a fast, diagonal slash across the pattern and toss it under his other arm, which is called a chop. Other old standbys include juggling an apple and taking the occasional bite or making a face by holding one ball in the mouth and the other two over the eyes. Many modern jugglers look on these tricks with contempt, feeling that tricks such as these keep juggling in the realm of the sideshow. To see examples of these variations, please refer to the video on the first page of the article.

Juggling By Numbers

Francoise Rochais and Anatoli Miagkostoupov juggle six clubs each.
Francoise Rochais and Anatoli Miagkostoupov juggle six clubs each.
Photo courtesy of Jack Kalvan

Three-ball juggling can be entertaining and challenging, but it's just the beginning. Jugglers have claimed to juggle up to 14 props at once. Juggling so many objects requires a lot of skill, speed and practice.

A general rule of thumb in juggling is that an odd number of props requires a crisscross pattern, in which the prop is tossed from one hand to the other. An even number of props requires two separate groups of objects juggled in each hand. For example, the standard four-prop juggling pattern is two props juggled separately by each hand. There are patterns that allow jugglers to cross even numbers or keep odd numbers separate, but it's usually OK to assume the general rule applies.

With an even number of props, a juggler must handle two or more objects in each hand. There are two main patterns for juggling objects one-handed. The first is the fountain, in which a juggler tosses and catches the balls in a circular pattern in one hand. The other is juggling in columns, in which each ball is tossed and caught at the same position, traveling only up and down without moving side to side. Once a juggler is able to handle more even numbers of objects, he must concentrate on the fountain pattern.

Fountain juggling can be either synchronous, meaning both hands toss and catch at the same time, or asynchronous, meaning the hands alternate tosses. Because most three-ball juggling patterns are asynchronous, beginners learning four-ball juggling often prefer to concentrate on asynchronous patterns.

In order to juggle greater numbers of props successfully, jugglers must toss their objects higher in the air. For a juggler, the height of his toss is proportional to how much time he has in between tosses. The standard five-ball pattern is usually a little higher than that of your typical three-ball pattern. Seven- and nine-prop patterns need even more height if a juggler is to maintain control. Jugglers call the practice of juggling large numbers of props, particularly in terms of competition, numbers juggling.

Different Props

Clubs are probably the second-most-common juggling prop behind balls (or bean bags, which are often lumped into the same category). To juggle clubs, a juggler will usually rotate the club with each toss. Tossing and catching a club after one full rotation is considered a single flip. Doubles, triples and quads are tosses that include multiple flips (two, three and four, respectively). It's also possible to catch the body of the club with a half rotation. Jugglers can toss the club from one hand to the other without rotating it at all, which is called floating the club.

Clubs come in several styles, though the two most common are European and American. European clubs have a narrower body and are very popular among professional jugglers. For one thing, it's much easier to recover after a bad spin with a European club, and it's easier to catch it by the body and give it a half or one-and-a-half spin on the next toss. The Juggling Information Service Committee recognizes a record of nine clubs or sticks juggled at once.

Some props are easier to juggle in large numbers than others. Here's a brief list of the more common juggling props and how they translate into numbers juggling.

Several common juggling props are closely related to clubs. These include knives and torches, as well as other unorthodox juggling props such as axes and chainsaws. Obviously, with these items it's more important for a juggler to make sure he catches the object by the handle. Most of these dangerous items are designed in such a way as to minimize injury should a juggler mistakenly under- or over-rotate a toss.

Rings are also common juggling props. A ring is a circular hoop, usually at least a foot in diameter. Rings tend to have very stable flight paths due to a gyroscopic effect. It's easier for a skilled juggler to manipulate a greater number of rings than other objects. The official record for the most rings juggled at once is 13, though some claim to juggle as many as 14. Jugglers can throw more than one ring at a time from the same hand with relative ease -- throwing multiple props at the same time from one hand is called multiplexing.

Another popular form of juggling takes place in bars. Bartenders specializing in flair juggling, manipulating bottles and cocktail cups in flashy displays of dexterity and showmanship. Bartender flair can involve toss juggling, bounce juggling and twirling displays, among other techniques.

Juggling with Others

A group of jugglers passing clubs.
A group of jugglers passing clubs.
Photo courtesy of Jack Kalvan

Part of the fun in juggling is playing with other people. Jugglers tend to be social creatures, and most cities and college campuses have a club or group of jugglers who meet regularly. Juggling lends itself to many different kinds of interaction, including cooperation and sabotage.

One popular game to play between jugglers is stealing and replacing. To steal from another juggler is to take at least one prop from his pattern as he's juggling. Replacing involves adding a prop to the pattern after stealing a previous prop. It's possible to steal all of another juggler's props as he's juggling and take over his juggling pattern. To do this, you stand in front of the victim and get a feel for the pattern. Once you feel comfortable with the rhythm, you reach across and catch the victim's tosses, one after the other, until you are juggling all of the victim's props. Of course, the victim could just steal the props right back. You could then constantly steal from one another with nearly every toss.

To steal clubs, you can stand to one side of the victim -- facing the same direction as he is -- and reach around to take over the pattern yourself. If done correctly, the pattern of objects will stay stationary as you take your victim's place. With the proper timing, you and another juggler can cycle through stealing the same set of clubs as they stay in the same pattern. To observers, it looks like the props are juggling the performers. You can also steal and replace clubs by standing in front of a juggler. When he begins to toss a club into the air, you can catch it by the body and put a second club into his other hand, completing the juggler's catch for him.

Jugglers can also juggle in tandem. Two jugglers stand close together -- one juggler acts as the left hand, the other the right -- and share the pattern of drops. Jugglers may stand side by side, face one another or even stand back to back.

Passing the Torch

Two jugglers practice passing.
Two jugglers practice passing.
Photo used in public domain image.

Passing is probably the most familiar and spectacular way jugglers can interact with one another. Jugglers orient themselves so that they can make one of their tosses to another juggler instead of to their other hand. The two (or more) jugglers must synchronize their patterns and then throw a prop to another juggler on a designated toss. You'll often see jugglers pass with clubs, as they are impressive and easy to see. Because of the way a club flips, a juggler must catch incoming clubs by raising their arm up so the forearm is perpendicular to the ground (assuming his partner used an underhanded throw -- over-handed throws require the catcher to hold his hands as if he were catching a normal toss).

There are many passing patterns, but the best known is the 3-3-10. In this pattern, two jugglers with six props first pass every third toss from the right hand to the other juggler. After three of those passes, the jugglers pass every second toss from the right hand. After three of those, the jugglers pass every toss from the right hand for ten throws.

At some juggling gatherings, groups of performers can participate in combat juggling. The objective is to be the last juggler juggling. It's an every-juggler-for-himself kind of competition that can involve dozens of jugglers bumping into each other at once. One common strategy is for a juggler to toss one prop very high while using his hands to bat at his opponents' juggling patterns. Other jugglers steal props from opponents in order to defeat them. Most groups use padded or soft clubs in combat juggling, and injuries are not uncommon.

There are several juggling organizations across the United States. The International Juggling Association holds a festival each year featuring workshops and competitions for hundreds of jugglers. The Internet Juggling Database has a list of local juggling clubs throughout the world. Most of the organizations are free and welcome new members year-round.

Juggling Physics

Airflite juggling clubs
Airflite juggling clubs
©2007 HowStuffWorks

The physics of juggling involves parabolic arcs, speed, velocity, acceleration, air resistance and the force of gravity. With clubs and similar props, you can observe the center of gravity. While jugglers tend to rely on instinct to tell them how hard and high to throw a prop, it's the physics behind it that really determines what works and what doesn't.

The most important force for jugglers is gravity. Without gravity, juggling would be impossible. Apart from the fact that the juggler would be floating lifeless in the cold emptiness of space without gravity, he would also lose all his props once he threw them (though that would help propel him in the opposite direction). Gravity makes juggling possible, but it also limits what jugglers can realistically accomplish.

An object's acceleration due to gravity is 9.8 m/s², or 9.8 meters per second every second. This means when you drop an object, every second it falls its speed will increase by 9.8 meters per second, as long as we ignore the effects of air resistance. When you toss a prop into the air, gravity immediately begins to act as a downward acceleration force. Because the acceleration of gravity is a constant, a juggler can only slow down a pattern by adjusting the height of his tosses. Higher tosses can become problematic, though, because small variations in throws can result in greater errors when the distance is increased. In other words, shorter tosses are faster but more accurate, while longer tosses give a juggler more time but sacrifice accuracy.

The mass of your props is also very important. Props with the same mass can be thrown with the same amount of force to maintain a smooth, controllable pattern. If you juggle props that have different masses, such as an apple, a club and a bowling ball, you'll have to adjust the force of each throw to maintain the correct height for your tosses. This is because objects with more mass have more inertia and are more difficult to accelerate.

With props like clubs, a juggler also must be aware of the prop's center of gravity. The center of gravity is the point of average mass distribution of an object. It's also the point around which an object will rotate. Most club tosses include at least one full rotation. Learning how much force to use when tossing and rotating a club becomes second nature for a juggler after a little practice.

Tossed props follow a path called a parabola, meaning acceleration acts in a vertical direction while horizontal velocity remains constant. The accelerative force is gravity pulling downward. While tossed objects usually have a horizontal velocity (unless thrown straight up into the air), the velocity is constant, so no force is acting in a horizontal direction. If you take air resistance into consideration, the path can't be called a true parabola. Still, air resistance is usually negligible when considering the relatively short distances involved in tosses, unless you're juggling in a hurricane.

Juggling Theory

It takes math and physics to keep these jugglers up.
It takes math and physics to keep these jugglers up.
Photo courtesy of Jack Kalvan

­It's not surprising that many jugglers are mathematicians or physicists. Juggling demonstrates not only some fundamentally important concepts in physics, but it also inspires people to create complicated theorems.

Claude E. Shannon, a brilliant mathematician, proposed a juggling theorem that elegantly describes the relationship between how long props are in a juggler's hands and how long they are in the air. Here's his equation:

(F + D)H = (V + D)N

  • F is the time a ball spends in the air
  • D is the time a ball spends in a hand
  • H is the number of hands
  • V is the time a hand is empty
  • N is the number of balls being juggled

Shannon's equation illustrates the importance of a juggler's hand speed when juggling. As N increases, the juggler begins to lose the ability to vary the speed of his pattern while keeping it stable. Remember, H will remain constant unless the juggler either sprouts more hands or another juggler comes into the pattern.

Shannon built a juggling robot from an Erector set. His juggling robot had two arms and could bounce juggle up to three small metal balls against a drum. Other engineers have built robots that can bat objects upwards indefinitely using complex algorithms to make corrections. The Web site for the company SARCOS features a video of a humanoid robot juggling a three-ball cascade pattern. The robot has cups for hands and makes each toss and catch in a smooth, fluid motion.

Mathematician Jack Kalvan proposed an equation that describes a spatially optimal pattern, meaning it "allows for the same amount of error at all points along the flight path where collisions are most likely" [Source: Juggling.org]. Kalvan's equations are complicated and concentrate on variables such as the arc of each throw, finding the best distance between the arcs made by throws from each hand, and the ratio between when a hand holds a ball and when hand remains empty.

Using Math to Juggle?

Why apply such complicated theorems to a game of catch? Apart from using math to help examine how the world works, it's also useful in the study of human movement. Juggling has played a role in human movement and perception studies in several important experiments.

One such experiment examined the role optical (or visual) information plays in maintaining a juggling pattern. Human movement scientists A. A. M. van Santvoord and Peter J. Beek knew that when someone juggles three objects, he can't possibly pay attention to all three at the same time. A competent juggler can continue catching balls while shifting his attention back and forth constantly. Santvoord and Beek set up experiments to see how much optical information a juggler would need to maintain a stable pattern. While most jugglers believe the peak of each toss is the most important part of a throw, Beek and Santvoord discovered that as long as jugglers could see about 100 milliseconds of the flight path of a ball, they could continue catching and juggling.

Beek and Santvoord also discovered that accomplished jugglers relied less on optical information than beginners. They theorized that experienced jugglers rely more on haptic information, which means they pay more attention to how their throws feel. An experienced juggler can feel if a toss isn't right and can adjust without looking. Some jugglers have proven that they can maintain a simple cascade pattern while blindfolded.

Juggling Through History

Artwork from an Egyptian tomb showing a group of jugglers.
Artwork from an Egyptian tomb showing a group of jugglers.
Image is in the public domain

How old is juggling? A tomb of an Egyptian prince has hieroglyphs showing a group of women toss juggling. Archeologists believe the tomb was built between 1994 and 1781 B.C. So far, this is the oldest depiction of juggling discovered.

Art from Thebes, Greece, Rome, India and Europe displays jugglers performing complex tricks. Written accounts of jugglers date back to 400 B.C. An ancient reference in the Talmud describes Rabbi Shimon ben Gamaliel, who could juggle eight torches at once. You can find jugglers in ancient Irish and Norse literature as well.

Up through the Roman era, it seems that people held jugglers in high esteem. Shortly thereafter, jugglers fell on hard times. People began to think of jugglers as immoral con artists. Written accounts lumped jugglers in with magicians and witches, citing them as corrupt manipulators.

In the medieval period, jugglers returned to popularity in literature and art. Artists drew jugglers throwing an unlikely number of torches or knives. Jugglers were also singers and magicians -- to be a juggler was to be a well-rounded entertainer, and most made their living traveling from one small town to another. The council of Nuremburg, Germany employed a juggler not only as an entertainer, but also a teacher. Juggling had shed its ignominious reputation.

Beginning in the late 1700s, jugglers also became an important act in circuses. Many circus clowns incorporated juggling into their acts, and the two forms of entertainment began to become entwined in the public consciousness. Modern jugglers often gripe about the public perception of juggling as a form of circus entertainment.

W.C. Fields began his career in show business as a juggler.
Image is in the public domain

Juggling also played a big part in vaudeville entertainment in the late 1800s and early 1900s. One vaudevillian juggler by the name of W.C. Fields later became famous for his acerbic wit and grumpy demeanor in numerous films. As vaudeville declined in popularity and circuses became more rare, jugglers began to develop their own stage shows, perform on street corners or become mathematicians.

In 1947, at a convention of the International Brotherhood of Magicians, a group of jugglers decided that the world needed an organization focused solely on juggling. They formed the International Juggling Association (IJA) and held their first independent festival in 1948. Beginning in 1969, the IJA held championship competitions for juggling. Competition eventually included divisions for performance quality, numbers juggling and individual and team performances. In 2000, juggler Jason Garfield formed the World Juggling Federation, an organization dedicated to securing television coverage of juggling competitions. Today sports channels like ESPN broadcast juggling competitions to a worldwide audience.

Other Forms of Juggling

Two jugglers practice contact juggling.
Two jugglers practice contact juggling.
Photo used under the GNU Free Documentation License

While most people think of toss juggling when you mention the word juggler to them, there are many other object manipulations that the term covers.

Contact juggling is a recent art form in which the juggler manipulates one or more balls through constant contact with his body. Popularized by juggler Michael Moeschen, who performed the contact juggling in the film "Labyrinth," the art requires finesse and control. One important concept in contact juggling is isolation. Isolation is the illusion that the ball stays in the same space no matter what the contact juggler does. An accomplished contact juggler can roll a ball across his body in smooth, gliding motions that seemingly defy gravity.

Another popular form of juggling is the manipulation of devil sticks. A devil stick is a rod that is slightly wider at the ends than it is in the center. The juggler keeps the devil stick in the air using two control sticks. Jugglers can toss devil sticks back and forth, twirl them around like a helicopter's blades and perform several other impressive tricks.

The diabolo is another favorite prop for jugglers. A diabolo is a spool that a juggler manipulates using a string tied to two sticks. A good juggler can spin the diabolo very fast, performing tricks like complex throws, grinds and loops on the string or even on the sticks themselves. Diabolos are sometimes called Chinese yo-yos.

A performer balances on a rola-bola while juggling.
Photo used under the GNU Free Documentation License

Plate spinning is yet another form of juggling. Jugglers balance spinning plates on rods, tossing them in the air and catching them again. Some plate spinning routines require a dozen or more plates all spinning at the same time.

There are several other acts of dexterity that fall under the juggling category, including balancing on a rola bola -- a board sitting on top of a cylinder -- or standing on the top of a freestanding ladder with no other support. Many jugglers incorporate balancing acts in their performances. Often you'll see a juggler balance a club on his chin or spin a ball on a rod while toss juggling other props.

Some toss jugglers feel that these and similar activities shouldn't be categorized with juggling at all. While they admit that performing these feats and tricks takes skill and practice, they say that it just isn't juggling. However, historically people have used the word "juggle" very loosely for all sorts of skillful displays. It's likely the boundaries of what people consider to be juggling will continue to grow as people find yet more ways to astonish audiences with prop manipulation.

To learn more about juggling, check out the links on the next page.

Related HowStuffWorks Articles

More Great Links

Sources

  • "juggler." Encyclopaedia Britannica. 2007. Encyclopaedia Britannica Online. 9 July 2007. http://search.eb.com/eb/article-9044099
  • Bebko, James et al. "Acquisition and Automatization of a Complex Task: An Examination of Three-Ball Cascade Juggling." Journal of Motor Behavior, Vol. 35, No. 2, 2003.
  • Beek, Peter J. "Timing and Phase Locking in Cascade Juggling." Ecological Psychology. Vol. 1, No. 1, 1989.
  • Beek, Peter J. and Lewbel, Arthur. "The Science of Juggling." Scientific American, Vol. 273, No. 5, 1995.
  • Cohen, Steve. "The Juggling Girls of Tonga." Whole Earth Review, Spring, 1988. http://www.juggling.org/~conway/cohen/
  • ContactJuggling.org
  • DiaboloTricks.com http://www.diabolotricks.com/
  • JuggleNow.com http://www.jugglenow.com
  • Juggling Information Service http://www.juggling.org
  • JugglingWorld http://www.jugglingworld.biz/about_steve.html
  • Kalvan, Jack. "Optimal Juggling: The analysis and over-analysis of juggling patterns." 1996. http://www.juggling.org/papers/OJ/
  • Lewbel, Arthur. "Research in Juggling History." http://www2.bc.edu/~lewbel/jugweb/history-1.html
  • Santvoord, A. A. M. and Beek, Peter J. "Phasing and the Pickup of Optical Information in Cascade Juggling." Ecological Psychology, Vol. 6 No. 4, 1994.
  • The Internet Juggling Database http://www.jugglingdb.com/
  • The Silver Man's Contact Juggling Page http://www.thesilverman.co.uk/contactsite/top.html
  • Voss, Jochen. "The Mathematical Theory of Juggling." http://seehuhn.de/pages/theory
  • Voss, Jochen. "The Physics of Ball Juggling." http://seehuhn.de/pages/physics
  • World Juggling Federation http://www.thewjf.com/
  • http://www.DevilStick.de