How padel works

Padel is a racket sport played in pairs, on a court enclosed by walls of glass and wire mesh. From the outside it looks like tennis in a box: there is a net, there are rackets, and the ball is very nearly a tennis ball. But a few rallies are enough to see that the box changes everything. In padel, a ball that gets past you isn’t lost. Once it has bounced, it’s allowed to rebound off the glass, and you can still play it.

The game was invented in 1969 by Enrique Corcuera in Acapulco, Mexico, grew up in Spain and Argentina, and has since spread around the world. In this article we’ll take it apart piece by piece: the court, the ball, how the ball bounces and flies, and how the walls turn what would be a winner in tennis into the middle of a rally. Along the way we’ll see why the lob is so valuable, why a serve that lands in can still be a fault, and how a smash can leave the court entirely.

Everything that moves on this page is computed live in your browser by a small physics model of the ball: gravity, air drag, spin, and friction during each bounce. The dimensions and rules are the official ones. The physical constants – how lively the floor is, how slippery the glass – are reasonable estimates, not measurements of any particular court, so read the simulated numbers as illustrative. The ball is also drawn larger than life so that you can see it.

The court

A padel court is a rectangle 20 m long and 10 m wide, divided in half by a net. The net is 0.88 m high in the middle and rises to 0.92 m at its ends. You can drag the court below to see it from any side, and use the buttons to pick out its parts.

There are surprisingly few lines. On each side a service line runs parallel to the net, 6.95 m away from it, which leaves 3.05 m between that line and the back wall. A centre line splits the space between the net and the service lines into two service boxes on each side. All lines are 5 cm wide. There are no baselines or sidelines, because the walls do that job.

The enclosure is what makes the court unique. Each end is closed by a wall 3 m high – on modern courts it is glass – topped with 1 m of metal mesh, for a total of 4 m. The glass then turns the corner and continues 4 m along each side as two steps: the first 2 m are 3 m high, the next 2 m only 2 m high. Mesh fills in the rest, up to 4 m above the tallest step and up to 3 m everywhere else along the sides. (The rules also allow a variant in which the side glass is 3 m high for the whole 4 m.)

The distinction between glass and mesh matters a great deal, as we’ll see. Glass is hard, flat and smooth, and the ball comes off it predictably. The mesh is a fence of wire rhombuses: the ball comes off it slower and in directions that are hard to anticipate.

Real courts also have gaps in the side fences, next to the net, for getting on and off the court – and, in some rallies, for running out after the ball. Our model leaves them out to keep the geometry simple.

The ball

A padel ball is a hollow rubber sphere covered in felt. It is between 6.35 and 6.77 cm across and weighs between 56.0 and 59.4 g. What the rules pin down most carefully is how it bounces: dropped from a height of 2.54 m onto a hard surface, a new ball has to come back up to between 135 and 145 cm.

In the demonstration below a ball is dropped from that height, and its height is plotted against time. The slider controls how much of its speed the ball keeps in each bounce.

That fraction is called the coefficient of restitution, written e: the speed of the ball just after the bounce divided by its speed just before. A ball falling from height h arrives with a speed proportional to √h, and needs the same kind of speed to climb back up, so, leaving aside the small effect of air resistance, e is simply the square root of the ratio of the two heights. For a ball to pass the test, e has to be between about 0.73 and 0.76.

Notice that each peak is the same fraction of the one before it, e², which is why a bouncing ball dies away so quickly. In reality e isn’t quite constant. A rubber ball loses a larger share of its energy in a harder collision, so a ball driven into the floor at speed bounces relatively lower than it does in this gentle test. The simulations further down take that into account.

The racket

Padel rackets have no strings. The head is a solid, flat paddle, drilled through with holes between 9 and 13 mm wide. The whole racket may be at most 45.5 cm long, 26 cm wide and 38 mm thick, which makes it much shorter than a tennis racket, and it must have a cord, which the player is required to wear around the wrist.

Rackets are sold on shape, weight, and the hardness of the foam inside them, each with a promise attached. It’s worth seeing what those things can actually do. In the figure below a ball arriving at 40 km/h meets a swinging racket. The curve above the racket shows how fast the ball leaves, depending on where on the face it lands.

Two things compete along the length of the racket. The tip moves fastest, because the racket swings in an arc. But near the tip the ball meets less of the racket’s mass and knocks the head back, so less of that speed gets into the ball. Close to the balance point the opposite is true. The most powerful spot is a compromise between the two, well above the balance point.

Now change the shape. A round racket carries its weight low, a diamond carries it high in the head, and a teardrop sits in between: by manufacturers’ guides, their balance points are typically around 25.5, 26.5 and 27.5 cm from the end of the handle. Moving the weight up puts more mass behind a ball struck high on the face, where the racket is moving fastest. That is the trade people mean when they call a diamond a power racket and a round one a control racket – though a head-heavy racket is also harder to swing fast, which this figure does not charge you for.

Then compare what each slider is worth, in the line under the figure. Swing speed dwarfs everything. A heavier racket helps a little. So does a livelier one – and that slider already covers the whole range that was measured: a laboratory that tested fifty padel rackets found that the most and least powerful differed by only 5 to 7%. The same laboratory found that a racket 20% heavier sent the ball about 4% faster, which is what this model gives too, and that a racket 20% stiffer changed the speed of the ball by about 0.3%. Whether the foam feels soft or hard in your hand has very little to do with how fast the ball leaves.

The same tests found something else. A ball bounces worse off a clamped padel racket than off a hard floor: it keeps about 66% of its speed, against 74% from the floor. A padel racket is not a trampoline. Nearly all of the speed in a shot comes from the swing.

How the ball bounces

So far the ball has only dropped straight down. In a game it arrives at an angle, usually spinning, and then two different things happen where it touches the ground.

Perpendicular to the ground, the ball squashes and springs back, keeping the fraction e of its speed. Along the ground, friction gets involved. What friction cares about is not how fast the ball is travelling, but how fast the bottom of the ball is sliding across the surface – and that depends on spin. On a ball with no spin, the bottom slides forward at the ball’s own speed. Backspin makes the bottom move forward even faster. Topspin moves the bottom backwards relative to the ball, which can cancel the slide entirely, or even reverse it.

Friction always opposes the slide. Because it pushes on the bottom of the ball and not on its centre, it changes two things at once: the ball’s forward speed, and its spin. If friction is strong enough to stop the sliding before the bounce is over, the ball grips the surface and leaves it rolling.

Drag the spin slider from one end to the other. With backspin the bottom of the ball skids hard against the floor, friction acts for the whole bounce, and the ball checks up: it leaves more slowly and at a steeper angle than it would have without spin. With topspin there is little sliding to oppose, so the ball keeps its speed and stays low. And if you make the approach steep and the topspin heavy, the bottom of the ball is moving backwards when it lands, friction pushes the ball forward, and it leaves faster along the ground than it arrived.

Through the air

Between bounces, three forces act on the ball. Gravity pulls it down. Air drag pushes against its motion and grows with the square of its speed, which makes it negligible for a gentle lob and surprisingly large for a hard shot: on a ball moving at 25 m/s, or 90 km/h, drag is stronger than gravity. And if the ball is spinning, it drags the air around with it and is pushed sideways in return, which is called the Magnus effect. Topspin makes the ball dive. Backspin holds it up.

Here you are hitting from the back of the court on the left. You can change the shot, and you can switch the air off to see what it contributes.

Spin

Spin has now turned up twice: it changes how the ball comes off the floor, and it bends the ball’s flight. Padel is played with a great deal of it, so it deserves a closer look. A ball can spin about any axis at all, but every spin is a mixture of three pure kinds, and they behave very differently.

Topspin and backspin share an axis, lying level and across the direction of flight. They differ only in which way the ball turns. Sidespin has an upright axis and bends the flight to one side. The last kind, with its axis pointing along the flight, does nothing at all in the air.

The court doesn’t treat these three equally, and that will matter a lot later on. The floor is flat, so it has no way to get hold of spin about an upright axis: sidespin goes through a bounce on the floor almost untouched, while topspin and backspin are rewritten by every bounce, as we saw. A wall is upright, so for a wall it is the other way round. The back glass takes hold of sidespin, and of whatever topspin the floor has just left on the ball.

Where spin comes from

A ball picks up spin when the racket face is moving across it at contact and not only through it. Brushing up the back of the ball gives topspin, cutting under it gives backspin, and swiping around its side gives sidespin. It’s the floor bounce again, with the racket playing the part of the floor: if the ball slides on the face, friction decides how much spin it gets, and if it grips, it leaves rolling.

That has a consequence which surprises many players. Rackets are sold with rough, sandy faces that promise more spin. But roughness can only matter while the ball is sliding.

At a glancing angle the ball slides, and the rougher face really does produce more spin. But past a certain angle the ball grips every one of the three faces, and from there on they produce exactly the same spin. The laboratory study those friction values come from found just that with real rackets: on the smoothest face the ball stopped sliding at 53°, on the roughest at 28°, and the authors concluded that for almost all padel shots, all rackets produce about the same spin. Spin comes from the swing, not from the surface.

The glass

A few figures ago, the verdict under the shot you were adjusting was quietly applying the most important rule in padel.

When you hit the ball, it has to cross the net and bounce on the floor of your opponents’ side before it touches their walls or their fence. If it reaches the glass or the mesh on the full, you lose the point.

But once the ball has bounced, everything on that side is in play. It can come off the back glass, the side glass, the mesh, or several of them in turn, and your opponents may hit it at any moment before it bounces on the floor a second time. They can even hit it into their own glass and let it rebound over the net – though not into their own mesh.

This turns tennis instincts upside down. In tennis, a hard, deep drive is a weapon. In padel, a hard ball that bounces deep runs into the back glass and comes right back out, towards a defender who has had plenty of time to get ready for it.

Raise the pace and watch what changes. The time the defender has stays almost exactly the same, about a second. What grows is how far the ball comes back off the glass. Extra pace doesn’t rush the defender. It just carries the ball further out into the court, to where they are waiting for it.

Now try the three kinds of spin. This is where the bounce from the previous section starts to matter, because the ball arrives at the glass with whatever speed and spin it has left after the floor.

A sliced ball skids on the floor and loses much of its speed there. It reaches the glass slowly and low, comes off it at about knee height, and bounces again almost at once. The defender gets much less time, and has to dig the ball out from close to the wall. A ball hit with topspin does the opposite: it keeps its speed through the floor, jumps off the glass, and floats a long way back at a comfortable height. This is why slice is everywhere in padel. Volleys and defensive overheads are usually cut, so that the glass gives the opponents as little as possible.

Here is the close-up from earlier, turned on its side: a ball arriving at the glass.

A ball that has gripped the floor leaves it rolling forwards, which is heavy topspin, whatever spin it had before. When that ball meets the glass, the side of it touching the wall is moving downwards. Friction pushes back, upwards, and the ball climbs: it comes off the glass rising more steeply than it arrived. Slide the spin over to backspin and friction points the other way, pushing the ball down towards the floor.

Keep that climb in mind. It’s the secret of the most spectacular shot in the game.

Corners

Seen from above, the glass behaves a little like the cushion of a billiard table, with one important difference. The glass gives back only part of the speed the ball had straight into it, while the speed along the glass is barely touched. So the ball doesn’t leave at the angle it arrived: it comes off closer to the wall.

Aim the ball into a back corner and it takes two walls in quick succession, side then back, or back then side. Players call this a doble pared, a double wall, and it’s one of the hardest balls to read, because the second wall sends the ball back out in nearly the direction it came from.

Aim it at the side fence nearer the net instead, and it meets the mesh. The mesh soaks up most of the speed the ball brings into it, so the ball comes away slowly and stays near the fence. On a real court it also kicks off the wire unpredictably, which no tidy model can reproduce.

The serve

Every point starts with a serve, and it is nothing like a tennis serve. The server stands behind their own service line, lets the ball bounce on the ground, and then hits it at or below waist height, with at least one foot on the ground. There is no throwing the ball up and no hitting it from above.

The serve goes diagonally, over the net, into the service box on the other side. It has to bounce inside that box – the lines count as in – and the receiver has to let it bounce. As in tennis, the server gets two attempts.

And then there’s the rule that is unique to padel. After bouncing in the box, the serve may hit the glass, but if it touches the mesh before its second bounce, it’s a fault. Tap or click anywhere on the far side of the court below to aim a serve.

Try a serve that lands in the box close to the side wall and near the net. It is perfectly in, and it’s still a fault, because that part of the side is fence. Aim deeper, and the same angle carries the ball into the side glass, which is fine – and awkward to return. That is why good serves are aimed deep and towards the glass.

The lob

In padel, the pair that stands at the net usually controls the point. From there they can volley the ball down at the defenders’ feet or angle it into the side walls, while the pair at the back mostly has to wait for the ball to come off the glass and send it back.

The defenders’ main way out is the lob: a ball lifted over the heads of the players at the net. If it’s good, those players have to turn around and chase it to the back of the court, and the defenders walk forward and take the net themselves.

A lob has to thread a narrow window. Too low or too short and it gets smashed. Too long and it reaches the back glass before it bounces, which loses the point outright. Add some topspin and see what it does: the ball dives at the end of its flight, so it can be hit higher over the net player and still come down inside the court.

Overheads

When a lob comes up short, the players at the net get to hit it out of the air, from above their heads. There is a whole family of these shots, and what separates them is mostly how much they risk.

The bandeja, the “tray”, is the safe one: a compact swing, the ball cut from underneath with a little slice, sent deep. It isn’t meant to win the point. Its only job is to keep the net. The víbora, the “viper”, is its aggressive cousin: struck on the outside of the ball, with more pace and with sidespin, usually towards the side glass, where it skids through low. And then there is the smash, which is an attempt to end the point there and then.

The smash

How hard is a smash? A radar study of competitive players aged 12 to 16 measured smashes averaging 112 km/h for the boys and 104 km/h for the girls, with the boys’ best efforts around 127 km/h. Another study, of adult players, found that they smash measurably slower when there are opponents on the other side than when the court is empty. And the ball doesn’t keep its speed for long: drag grows with the square of speed, and in our model a smash loses about a fifth of its speed to the air alone over 12 m of flight.

Here the smash is hit from 2 m back from the net, with the racket 2.7 m above the floor. You choose how hard it is hit, where it comes down, and how it spins.

Start with a gentle one, around 80 km/h, landing in the middle of the court. It meets the glass and comes back to the defenders, which is exactly what happened to the hard drive earlier. Now add power. At around 100 km/h the rebound becomes so long and so high that the ball sails back over the net. The smash returns to the side it was hit from, and unless a defender catches it on the way, the point is won.

Then try the spin. Slice takes the life out of the rebound, and the same smash needs noticeably more power before it comes back. Topspin does the opposite, for the reason we saw at the glass: the ball climbs. With topspin the smash comes back over the net from much lower speeds.

You could explore all of this one smash at a time. Or you could look at every smash at once.

Each point on the map is one smash: how hard it was hit, and where it came down. There are three regions worth knowing. Along the bottom are the smashes that are simply too soft, which the defenders play off the glass. Above them is a broad band of smashes that come back over the net. And squeezed into the top left corner is something else: smashes brought down very close to the net, which strike the floor so steeply that they rear up, first into the mesh above the glass, and then over the 4 m wall and out of the court.

That corner is small for a reason. What sends a ball over the back wall is not its speed along the court but its speed into the floor, and only a smash hit from right on top of the net comes down steeply enough. Switch the spin and the whole map redraws: with topspin the band of returning smashes reaches far down towards the gentle ones, and with slice it retreats to the top.

The kick

Going out over the back wall takes a huge smash from right at the net. But there is another way out of the cage, and it needs much less power, because it uses the glass.

Think back to the ball climbing the glass. A kick smash is hit with heavy topspin and aimed to bounce close to the opponents’ service line. It reaches the back glass low down, climbs it, and comes away rising steeply. Hit straight, it flies back towards the net, as on the map. But hit across the court, it keeps drifting sideways as it rises – and the side fence is only 3 m high.

The buttons below load four overheads, each simulated like everything else on this page. After that it’s all yours to change: tap the court to move the bounce, and drag the sliders.

Load the kick smash and take the topspin off. Coaches describe this shot as a topspin shot first and a power shot second, and the model agrees. Hit flat at this spot, the ball needs about 113 km/h to clear the side fence. With 3,000 rpm of topspin it goes out from about 91 km/h.

Now move the bounce. In our model the ball goes out when it bounces between about 2.5 and 5 m from the back glass, which is a window around the service line – right where coaches say to aim. Outside that window it comes off the glass heading back down the court instead of across it.

And try the sidespin, which the floor can’t touch but the glass can. One way, the glass throws the ball at the fence even sooner. The other way, it steers the ball back into the court.

The bandeja and the víbora are the opposite idea. Both are cut, so that the glass gives nothing back: after the glass, neither ball gets much above a metre. The bandeja does it with backspin alone. The víbora adds sidespin and goes through the corner, off two panes of glass in turn.

Players name the winners after the height of the fence the ball clears: out over the 3 m side fence is a por tres, and out over the 4 m at the back is a por cuatro. A ball that leaves over the back wall ends the point there and then. One that leaves over the side is still alive on courts set up for it: the defenders are allowed to run out through the gap by the net and hit it back in before it bounces again.

Every shot

To finish, here is the whole court again, with every stroke we’ve met. Pick one, put the player and the target wherever you like, and see what the ball does. The other three players take up the positions that stroke is usually played against: at the net when you are defending from the back, and at the back when you are the one attacking.

A few things worth trying. Play the lob, then shorten it until the player at the net can reach it. Play the drive at the players at the net and see how comfortably they meet it, then play the chiquita at the same players. Walk the bandeja back towards your own glass and watch what it gives the defenders. And take the kick smash, slide its target along the service line, and find where it stops leaving the court.

The game

Points are counted as in tennis, and matches are the best of three sets. Almost everything else follows from the few things we’ve looked at: a lively ball, a small court, and walls that keep the ball in play.

Because the glass returns pace, hitting hard is rarely enough to win a point, and rallies are long. Because the net is the strong position, most of a rally is a fight over who gets to stand there: lobs to push the other pair back, low balls at the feet of the players at the net, careful overheads to hold on. And because the floor turns steepness into height, the players at the net are always waiting for one short lob they can bring down hard enough to send out of the court.

The rally at the top of this page goes through all of it. It’s worth another look.