So juggling's pretty hard.

At least for me it is.

Once you get to three balls,

there's this natural question, right?

Like, can you do four, maybe five?

What's the limit?

This guy definitely knows.

Hi, I'm Alex Barron, and I hold the world record

for most balls juggled.

That's 11, and I also hold the world record

for something called most balls flashed, and that's 14.

That's right, Alex has flashed 14 balls.

Flashed just means

throwing a certain number of balls in the air,

and catching that many balls in sequence, one time.

Here he is flashing 13 balls.

But is 14 balls the limit?

Today we're going to look at why juggling 15 balls

might be almost impossible.

To learn what it takes, I got a lesson from Barron.

It's close.

[Robbie] Talked with a juggling pro

about the patterns and science that make it possible

to keep so many balls up in the air,

and with someone who doesn't even have to see the balls

to juggle.

People have been juggling for millennia.

This Egyptian painting of women juggling

is nearly 4000 years old.

And it's always seemed like a bit of magic,

even three ball juggling is mesmerizing to watch.

But performers have always been pushing the limit

for higher numbers.

Back in the 1920s, famed juggler Enrico Rastelli

was said to have juggled 10 balls.

And for awhile, that seems like the upper limit

for continuous juggling.

People could match it, but nobody could really exceed it.

That was, until 2012,

when Barron managed this astounding feat.

11 balls for 23 catches.

I bloody did it, 23.

On camera, I think.

It feels good, yeah.

Like, I was very happy when I got the world record.

I mean, I wouldn't have spend so many hours doing it

if I didn't care about it.

[Robbie] Barron started juggling as a kid.

[Alex] I was determined to be one of the youngest people

to do 11, like for a flash.

Like you know, first you're like, yeah, I'll learn five,

and you hear people talking on the internet

about how hard five is.

Like, aw, I'm gonna be able to do five.

And then it just kinda keeps going from there.

So I don't think I'll ever have the time

or maybe more likely the patience,

to ever become a serious numbers juggler.

But I can already do three,

so Barron gave me some lessons on how I can do five.

So if I want to graduate from three balls to five balls,

you're talking about some of the things I need to work on

are my actual hand speed? Yup.

And how hight I'm throwing the balls,

because ti's the timing between the the throws, right?

Exactly, yeah.

You'll have to go higher and faster, probably.

Okay, so show me how that works.

(laughing)

Yeah, how that works.

Yeah, so with five, I'm gonna end up throwing them

about eyes level, or a little bit higher,

as opposed to low, with three.

But otherwise, it's the same.

Really, the motion is very similar,

you just have to be a little bit more fluid,

and yeah, move your hands a bit faster.

The hardest bit is the start,

because that's when you've got all the weight in your hands.

So to begin with, yeah, I just try,

don't even worry about catching them,

just go one, two, three, four, five and then just ...

So here we go, I'm just gonna do

one, two, three, four, five,

see if I can just get them all up in the air,

or if I can throw the last ball

before the first one comes down, right?

Sounds right, yeah, exactly.

Go, one, two, three, four, five.

Even faster would be better.

That's pretty good.

If it goes really well, what you want to see

is two little piles, one for each hand,

at the end of the fall.

Aw, man, all right.

But you can try and catch them, too.

That's just to get the speed.

I just want to see if I can get the speed again.

So yeah, one, two, three, four, five.

Yeah, that's pretty good.

And now try and catch them.

[Robbie] I've got five piles!

(laughing)

I managed to pull off a lucky flash

when the cameras weren't rolling,

and I'm still working on doing it continuously.

Really working on it.

Oh, that was close!

[Robbie] These days, five is just a warmup for Barron.

He can do seven without much trouble,

and makes it look effortless.

But when he starts going for big numbers, like nine, 10, 11,

all the way up to 14, he usually heads indoors,

to a squash court.

We're outside right now. Yes.

It's a little windy.

That has something to do

with why you practice in squash courts.

Yes, well wind, obviously,

is gonna mess up your pattern a little bit.

You want the balls to have a very consistent trajectory

every single time you try.

And the squash courts have really good contrast too,

because it's basically a white background.

So typically, it's much easier to see.

And even if you're not looking at one ball in particular,

your subconscious is still taking in

where they all are in the sky,

and where they're coming down, so.

[Robbie] Keeping an eye on the balls

at the top of their arc, or apex,

is critical for Barron's big numbers.

You look vaguely at the apex of the pattern,

and then from that you have some sense

of what the pattern looks like,

whether it's slanted, off kilter,

it's not like me registering,

you're just throwing and going,

oh, that was a good one, that was a bad one.

I guess I think that was a bad one.

If I do a bad throw, I typically notice

that ball in particular.

[Robbie] But that's not the only way

to juggle a lot of balls.

My name is Zak McAllister.

I hold three different records for BBB,

which stands for Blind Behind the Back juggling.

I hold the record for doing it five, sex, and seven.

[Robbie] McAllister doesn't have to

look at the balls at all.

He feels for their apex.

I'll start with them behind the back,

and I'll make my first throw, and once the throw is made,

then I wait to fell it hit my elbow,

and once I feel that,

then I know it's ready for the next ball.

Usually in my head, I'll feel out, be like,

okay, at this point, when I feel this,

I need to make this next throw.

Once I feel it coming down to my wrists,

then I know that

I need to open up my hand and have it ready

so that way I can make the catch.

[Robbie] It is crazy impressive.

But McAllister thinks he's at the numbers limit

for blind behind the back.

As you increase each ball,

you start to realize I'm running out of space on my back,

and four balls isn't too bad,

but once you hit five balls, you're starting to realize

I need to either, like,

start making my throws a little higher than my elbow,

which is not ideal, 'cause then it's even more blind,

and I have to think about it even more,

which takes up to like seven,

so you just have to hope that they all work out.

[Robbie] Traditional numbers jugglers

don't have the kind of limit.

In fact, the sky is literally their limit.

But it seems like there are physical barriers

to getting more balls in the air.

Let's talk about 15 for a second, for example,

just for the flash.

I do think there's a physiological barrier there

where someone will have to train very, very specifically

for flashing that number.

Doing 15 is going to require a level of strength

which is considerably beyond what I have at the moment.

[Robbie] To learn more, I talked with Jack Kalvan.

He's a professional juggler and former engineer,

and he's writing a book on human performance and juggling.

Kalvan has been measuring juggling hand speed

with an accelerometer and a a smart phones app.

So naturally, we asked Alex Barron to try it out.

Now juggle three balls in a comfortable cascade pattern.

[Robbie] First, Kalvan had him juggle

progressively higher numbers of balls.

Do you want to try a run of nine?

[Robbie] And then he had him try

an absurdly fast air juggle.

That's so unrealistic!

[Robbie] Perhaps, not surprisingly,

Barron topped Kalvan's charts.

Balls, according to his maximum hand speed,

when he shook his hand as fast as he could,

it was equivalent to juggling 23 to 25 balls.

So he's actually nowhere near his limit,

according to his hand speed.

That's crazy.

But according to Kalvan, speed is not the only limit

when it comes to numbers juggling.

Basically what I found was that hand speed

is not the main limiting factor of juggling.

It's actually the accuracy.

There's a few different degrees of accuracy,

but the first degree would be to throw something up

so that it lands within reach.

The other is the space that you have in the air,

and having to avoid collisions between objects.

[Robbie] Of course, I wanted to find out how I stack up.

So I strapped on the accelerometer.

We have three ball data here.

[Robbie] Okay.

Wanna do two in one hand?

Yeah, so,

there's a couple of ways to do this right?

You can do it in columns, is that right?

Yup, yup.

Put the balls down and shake your hand as fast as you can.

Faster, come on, faster!

You can go faster than that!

Is that all you got?

That's all I got.

Come on!

Okay, that's good.

[Robbie] And, according to Kalvan's calculations ...

Your maximum amount was 14.1 balls.

Sweet.

So if I practice really diligently,

I could maybe flash the 14?

You could.

You have the hand speed to flash 14 balls, just like Alex.

Okay.

But you probably don't have the accuracy.

An incredible, incredible dearth ...

So I'm still working on five.

But it's nice to know that I have the hand speed

to do more than that, if I keep practicing.

In fact, according to Jack's research,

most people probably have the hand speed

to do as many as nine.

I'm actually a professional.

Nope.

(laughing)

So hand speed is definitely a factor to consider here.

But here's another big one.

How do you even hold this many balls?

Jugglers call it the grip.

So yeah, in terms of the grip,

we start off just very simple, one in each hand.

We move to two, you end up with a little line,

this one further out goes first.

Three is a little triangle.

I like to release this one first.

Four, so some people stack it on top,

which maybe you do for lower numbers,

but we're gonna go high, so we can't do that quite yet.

You end up with this little diamond.

Five, I like this kind of

trapezium shape.

Six in one hand, suddenly you get this pretty ugly

two lines of three deal.

This one, as you can see, is pretty compressed.

This is probably the worst one to release.

If you get up to 14, then you just shove

the last two on top.

Really any time, you can shove the last two on top,

but with 14, we're forced to go like this.

I do these little setup throws

to try and get them in the right position.

[Robbie] Barron is a pretty tall guy.

He's over six feet tall, and he's got big hands.

But what about there rest of us?

Like that?

Ah ha!

Missing a ball. (laughing)

I don't think my hands are big enough for this.

[Robbie] Okay, so not all of us are up for

massive numbers juggling.

14!

[Robbie] But there are other ways to impress,

mathematically, of course.

There's the beauty of something called side swap.

So side swap is a way of notating juggling patterns.

So you could throw balls at different heights

when you juggle, and the way jugglers

typically denote those different heights

is they do it based on how high you'd have to throw

to juggle a certain number of balls.

So for three balls I can do it really low, like this, right?

If I pick up five balls,

just 'cause there are more balls,

I have to throw it higher to do the same thing.

So what side swap lets you do

is combine throws from different numbers of balls,

and you just call those throws the number of balls.

So, a simple one, for example, with four balls,

would be something called five three four.

And so if was just doing four, right,

and they all go the same height.

So this is lots of fours over and over again.

What I can do is I can throw one ball higher,

to be a five, and one ball lower to be a three,

and then go back to four.

So that's like five three four.

You can see there's a five ball throw

and a three ball throw.

And then you can either do five three continuously,

or you can mix it up.

And yeah, what's fun about that is now,

if you want to tell your friend,

hey, I found this great new juggling pattern,

you just give him a list of numbers,

and then they can do it.

Or they can try and learn it, at least.

[Robbie] Side swap can even be a way to practice juggling

in greater numbers, according to Kalvan.

Side swap is a way that you can,

that some people practice higher numbers

using a lower number of balls.

In this pattern you're actually throw,

one hand is doing the work of five balls.

One hand is doing exactly

is doing half of a five ball pattern,

and the other hand is doing a one ball pattern.

Which is just that.

[Robbie] That's useful, because

practicing big numbers can be a serious workout.

The raw physical act of it,

like the speed at which you have to move your hands,

the weight that you have in your hands at the beginning,

is on a different level.

People tend to see, in the juggling world,

going from an even number to an odd number

as being substantially harder

than going from an odd number to an even number.

With even numbers, you can throw them in pairs,

which means you can get your whole body involved.

With 15, you'd have to do it asynchronously.

The biggest question mark for me is probably

whether someone has the physical ability

to practice 15 enough to be able to do it,

or have enough attempts to be lucky enough

to catch 15 balls.

'Cause of course there's luck involved.

[Robbie] Between the practice needed to perfect technique,

and the strength and speed required

to keep the balls in the air,

Barron thinks his record will stand.

But he's eager to see it challenged.

Yeah, do I ever think someone will do 15 for a flash?

I like to think someone will do 15.

I mean, you compare this to like the 100 meter sprint,

or a marathon or something,

where countless people have optimized themselves

as hard as they can, and trained for it.

I think there's more to go in juggling for sure.

I don't know if that's within my personal limit,

but I'll intend to find out over the next 10 years or so.

Beyond that, I mean, yes,

I think there is a physical limit at some point, right?

And for me, ti's hard to conceive of juggling 16 or 17,

or flashing 16 or 17 balls.

Maybe I should say that 15 isn't possible,

and then some guy will come along, and be like,

or some girl, and be like, no.

Screw you, I'm gonna do it.

So I've been practicing a few minutes every day,

and every once in a while, I'll get lucky,

and flash five.

And I finally managed to do it on camera.

(beep) yeah! (laughing)

So, there's hope,

but it's not like I'm ever gonna challenge

somebody like Barron.

And that's totally fine.

Because what he's doing is already almost impossible.