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Tennis Court Surfaces and Court Speeds

What Court Surfaces and Tennis Balls Do Grand Slams and ATP Tournaments Use? What Speed Are They?

Earlier this week the US Open announced that they were changing the brand of court surface used at the tournament for the first time in more than 40 years.

The switch sees Flushing Meadows use Laykold hard courts made by Advanced Polymer Technology, replacing the DecoTurf that had been in use since 1978.

This change in New York follows on from Melbourne's change earlier in the year. The Australian Open moved surface supplier to GreenSet Worldwide for 2020 away from California Sports, who they had used since 2008.

We've also seen several ball changes in recent years with Dunlop striking a massive deal to supply the Australian Open Ball and Wilson replacing Babolat as the French Open Ball.

With that in mind, what other court surfaces and tennis balls are currently in use on the ATP tour? Are we moving even further towards surface homogenisation and just one or two suppliers dominating? Let's take a look.

Grand Slam Court Surfaces, Court Speed and Tennis Balls

Aus Open Dunlop Balls
Tournament Supplier Surface ITF Court Pace Rating Ball Used
Australian Open Greenset Worldwide Australian Open GreenSet Category 4 – Medium-Fast Dunlop Australian Open
French Open Supersol Red Clay Category 1 – Slow Wilson French Open
Wimbledon Mother Nature 100% Perennial Ryegrass N/A Slazenger Wimbledon
US Open Advanced Polymer Technology Laykold Cushion Plus System Category 2 – Medium-Slow Wilson US Open

ATP Masters 1000 Court Surfaces, Court Speed and Tennis Balls

Masters 1000 Balls
Tournament Supplier Surface ITF Court Pace Rating Ball Used
Indian Wells California Sports Surfaces Plexipave IW Category 2 – Medium-Slow HEAD Penn
Miami Masters Advanced Polymer Technology Laykold Cushion Plus Category 2 – Medium-Slow HEAD Penn
Monte Carlo Terre Davis S.a.s. Red Clay Category 1 – Slow Dunlop Fort Clay Court
Madrid Open Celabasa Sport Red Clay Category 1 – Slow Dunlop Fort Clay Court
Rome Masters Terre Davis S.a.s. Red Clay Category 1 – Slow Dunlop Fort Clay Court
Rogers Cup California Sports Surfaces DecoTurf II Category 3 – Medium HEAD Penn
Cincinnati Masters California Sports Surfaces DecoTurf II Category 3 – Medium HEAD Penn
Shanghai Masters California Sports Surfaces DecoTurf II Category 3 – Medium Dunlop
Paris Masters Greenset Worldwide Greenset Grand Prix Category 3 – Medium HEAD Penn
ATP Finals Greenset Worldwide Greenset Grand Prix Category 3 – Medium Dunlop

ATP 500 Court Surfaces, Court Speed and Tennis Balls

Tournament Supplier Surface ITF Court Pace Rating Ball Used
Rotterdam Greenset Worldwide Greenset Grand Prix Category 3 – Medium Technifibre X One
Rio Open   Clay Category 1 – Slow HEAD Penn
Dubai California Sports Surfaces DecoTurf II  Category 3 – Medium Dunlop Australian Open
Acapulco California Sports Surfaces Plexipave Category 1 – Slow Wilson US Open
Barcelona Celabasa Sport Clay Category 1 – Slow Dunlop Fort Clay Court
Halle Mother Nature Grass Unknown Slazenger Wimbledon
Queens Mother Nature Grass Unknown Slazenger Wimbledon
Hamburg   Clay Category 1 – Slow Tretorn
Washington California Sports Surfaces DecoColor Category 4: Medium-fast HEAD Penn
Beijing California Sports Surfaces DecoTurf Category 3 – Medium HEAD Penn
Tokyo California Sports Surfaces DecoTurf Category 3 – Medium Dunlop
Basel Greenset Worldwide Greenset Grand Prix Category 3 – Medium Dunlop
Vienna California Sports Surfaces Rebound Ace Synpave Category 2 – Medium-Slow Dunlop

What Other Types of Court Surfaces are Used Across the World?

Carpet Court

Tennis is probably one of the few games in the world that is played on a variety of surfaces be it grass, clay or hard courts each of those surfaces has smaller subsets made up from different materials like concrete, artificial grass and acrylic.

All court surfaces go through a rigorous testing procedure before they can be approved as an official surface by the ITF, the tests take into consideration friction, energy restitution, topography and consistency.

The types of Tennis Court officially in use across the world are:

  • Acrylic / Polyurethane
  • Artificial Clay
  • Artificial Grass
  • Asphalt
  • Carpet
  • Clay
  • Hybrid Clay
  • Concrete
  • Grass
  • Other, e.g. tiles, wood, canvas and modular systems.

How is the Speed of a Tennis Court Surface Measured?

A Sestée in Action

The ITF measure the speed of a surface using a system called Court Pace Rating or CPR for short. Any court that is used for a tournament has it's own unique Court Pace Rating.

The Court Pace Rating System measures the effect the surface has on the tennis ball which again takes into account friction, which looks at how much the balls velocity changes after it has hit the surface and also vertical restitution which factors in the time between successive bounces.

The CPR test needs various apparatus to be carried out including something to fire out a tennis ball at a set speed such as an air cannon and then a piece of equipment known as a Sestée, pictured above.

I won't go into the complexities of how it works, but basically, the Sestée uses laser technology in its two boxes that can reconstruct the trajectory of the ball and calculate pace. The ball is released from the cannon at 30m/s and at a 16° angle with no spin being imparted on it.

The Sestée can measure the following:

  • Vix = horizontal inbound velocity (m/s)
  • Viy = vertical inbound velocity (m/s)
  • Vfx = horizontal outbound velocity (m/s)
  • Vfy = vertical outbound velocity (m/s)
  • e = coefficient of restitution (COR)
  • μ = coefficient of friction (COF)
  • T = mean ball temperature for test location/sample (°C)
  • c = temperature coefficient (0.003)
  • eT= adjusted COR for temperature T
  • a = pace perception constant (150)
  • b = mean coefficient of restitution for all surface types (0.81)
  • CPR = Court Pace Rating

where:

CPR Equation

Once the pace of the courts has been measured, they are placed into categories:

Category Court Pace Rating
Category 1: Slow ≤ 29
Category 2: Medium-slow 30-34
Category 3: Medium 35-39
Category 4: Medium-fast 40-44
Category 5: Fast ≥ 45

What is Court Pace Index?

court-pace-index-wtf-historical

Court Pace Index is a completely independent method of measuring court speed and comes directly from Hawkeye.

Using their triangulation camera system, they can calculate the speed from in tournament play.

CPI shows the actual speed of the courts as it's measured during real matches on the main show courts throughout the tournament to produce an average over seven days.

CPI is calculated from the following:

CPI=100(1-μ)+150(0.81-e)

  • Where μ is the coefficient of friction
  • e is the coefficient of restitution

Again please remember here CPR = an ITF speed rating given to surfaces in a lab. CPI = court speed calculated from Hawkeye data from the main show courts during a tournament.

Examples of Court Pace Index

Speeds in 2016

Court Page Average

Speeds in 2017

The Australian Open is not listed here, but it was rated at 40.

court-pace-index-2017

Additional Reading

How to Solve the Court Speed Problem

court-pace-index-hawkeye

Most players and fans are acutely aware that the surfaces have slowed down over the years. This done for a variety of reasons but the main one is to do with the length of matches and TV money. 

The video below from 2013 talks about this at the fifty-second mark:

My opinion is that there needs to be more variety, so players have to adapt. One solution would be that an outside body predetermines the speed of the court at any given tournament and it can't change year on year or at the discretion of the tournament organisers.

So as an example, the US Open has to play at a set speed every year, and it can't drop below or exceed an agreed threshold.

There'd be no more putting more sand into the Laykold mixture to make the surface rougher; it'd be made the same each year for all of the courts at Flushing Meadows. And it'd be a fast hard court, as it should be.

By using that approach, you'd be able to have a wide variety of court speeds on tour. With the right rules in place and planning, it'd be possible to have courts ranging from one end of the spectrum to the other throughout the year.

This allows players to be tested on a variety of surfaces of which some play super quick, some play in-between, some bounce high, some bounce low and some play slowly. The key is variety, and I think you will only get that with some kind of regulation in place.

Frequently Asked Questions

Clay Supplies

Some common question I've received after writing several posts about court speed and surfaces over the years.

What is the ITF Court Pace Rating?

Court Pace Rating

The ITF classifies surfaces into one of five categories according to its Court Pace Rating: 1 – Slow, 2 – Medium-slow, 3 – Medium, 4 – Medium-fast, 5 – Fast.

This is not a measure of the speed of the court at the tournament it is used; it is purely the speed of the surface when it goes through classification. 

For example, if I create a surface called peRFect Speed Plus and I want to be classified by the ITF, I'll submit details of the surface and supply a sample of it to be tested to receive its court pace rating.

A surface type can have multiple classifications to provide a more extensive offering for buyers. Laykold, for example, has the Cushion Plus surface available in Category 2, Category 3 and Category 4.

You can see an example of a surface classification certificate here.

How Do Tournaments Determine Court Speed?

Laykold Speed

Tournaments will first seek a court supplier to lay the courts for their tournament. For example, the US Open has chosen a company called Advanced Polymer Technology for 2020.

The choice is usually determined by the surfaces the supplier produces or has access to. In the case of the US Open, Laykold is the surface of choice.

From there it's a case of the tournament and the supplier liaising to produce a surface that plays at the speed a tournament wants.

A good example here is Miami, which like the US Open is played on the Laykold Cushion Plus System. They wanted a surface that had a similar speed to other ITF 3 Medium Pace-Rating tournaments.

The supplier then customises its product mixture and installation to tweak the ball speed to get the desired result. This is done by changing the underlying layers of court and the topcoat, which has sand particles in which impact ball speed.

The key takeaway here is that surfaces can be altered significantly in speed and they do not just come as an out of the box solution that plays according to their ITF rating.

Are All Clay Courts The Same?

Clay Bricks

All clay courts at tour-level are mostly the same as they're produced from red brick dust. However the way they're laid, the substrate and the underlying surface can differ.

For example, the French Open has the following composition:

  • Redbrick dust: 1 – 2 mm
  • Crushed white limestone: 6 – 7 cm
  • Clinker (coal residue): 7 – 8 cm
  • Crushed gravel: at least 30 cm
  • Drain

Not every surface uses this ballast, and not every court is laid in the same area. Some areas have better natural drainage, different soil, no need for textile sheets to prevent weed growth etc. which all affect how a court plays.

At the recreational level, clay courts are laid in a variety of ways, usually to reduce maintenance costs. For example, in Europe, the Red Plus system is prevalent, which uses multiple layers of filled carpet offering the same playing properties as a traditional clay court. 

Why Do Tournaments Use Different Tennis Balls?

Wilson Us Labs

The reason tournaments use different balls is purely down to sponsorship reasons. Tournaments are free to strike deals with whichever suppliers they wish.

The Australian Open signed a deal with Dunlop in 2018 for them to be the supplier of the Australian Open Ball, cutting ties with Wilson who had supplied the ball for several years.

Although all balls used on tour have to have a level of uniformity, and consistency in performance. They do play differently; some are lighter, some have different felt, some fluff up more.

This changes their speed through the air, how much moisture they absorb, their durability, and how they react with the strings. Several players believe changing balls between tournaments can lead to injury.

How Often Do Tournaments Change Surfaces and Balls?

Slazenger Wimbledon Ball

Most contracts for surfaces tend to run at around the four or 5-year mark and are renewed in most cases. Decoturf, for example, was used at the US Open for 41 years before they switched. 

Balls do change slightly more frequently, and this is usually because of player feedback and tournaments often change when the minimum contract term is over.

Take the French Open ball which was supplied by Dunlop until 2011, it then changed to Babolat which wasn't too well received from the players but they stuck with it. However, Wilson is the new provider of Roland Garros tennis balls from 2020 onwards.

On the flip side, Slazenger has been the supplier of the Wimbledon ball since 1902, probably the longest partnership deal in the history of any sport.

Got any questions or points of view about court surfaces, the speed of the courts or the balls in use? Let me know in the comments.

Jonathan

Huge fan of Roger Federer. I watch all his matches from Grand Slam level right down to ATP 250. When I'm not watching or tweeting about tennis I play regularly myself and use this blog to share my thoughts on Federer and tennis in general.

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18 Comments

  1. Good article, Jonathan. The sad part is, as we’ve all discussed, the courts are way slower and our man’s success on tour suffered because of it.
    Having different court speeds throughout the year makes things way more interesting. Too bad that doesn’t happen.
    At this point in time, the courts could all be deserted and wild animals have taken over.
    One question I do have, only 1-2 mm for red brick dust? Seems not enough? Wasn’t the original clay from flower pots?

    1. I believe that they originally covered the courts (grass at the time) in terracotta dust so that they wouldn’t wilt in the sun, and it changed the court speed and bounce. They figured it out and changed it to all clay as a new surface.
      I don’t remember where I read this, and it could be a figment of my imagination and or a fake story I read somewhere. Don’t know how true this is but still a cool story

      1. Makes sense so it will be true. I didn’t know it was done to cover the grass initially ( I thought they had just put a whole new surface down as a test rather than adapted grass.) but I know they discovered it because the grass was impossible to maintain in the South of France.

    2. The courts are definitely slower. In some ways, Fed has profited from it though as well, so it’s not totally bad for him. I just think there should be a mixture irrespective of who it benefits just to keep it interesting.

      Yes, I think they were made from terra cotta pots by the Renshaw brothers then they changed to crushed brick.

      And ye there is only 1-2mm of brick dust, the underneath is limestone, but it takes on the colour the dust which is why you think there is much more of it. If there was more of it, I think the court would be completely unstable and slippery with even more bad bounces.

  2. I also thought that the brick dust layer was thicker. After a heavy shower the white limestone can show especially if the court maintenance is poor.

    About tennis balls, I’m very curious about the outcome of the following, since I never got to talk to the customer: every year my company produces and sells several tens of tonnes of yellow acrylic fiber (whose colour was matched by yours truly) for Penn USA. I have no idea whether the balls made it to the professional tour or if they are only for recreational use. But the samples we got feel nicer that the standard polyester felt. Needless to say, most of them have vanished from the show room…

  3. Thanks Jonathan.
    First, I don’t know why this year’s AO is considered Medium-fast, it was slower than ever. Also, the Court Pace Index says that in 2016 the surface in London was measured 40.6 in one image and 42.1 in the other one, what the hell.
    I agree with you, diversity is the key and it was like that in the 2000s. Or at least we need seasons with a specific set of court speed (Medium for Australian Tour, Slow for IW-Miami, Fast for US Open tour, Medium-fast for Finals, etc).

    In my club we used pure brick dust.

  4. Please.
    Could anyone help me.
    Where can I find these numbers… for instance, is there an official information at the ITF website that shows me the speed of US Open surface?

    Thanks

    André Lemos

    Typing from Brazil

    1. The speed ratings are in my table above.

      Only CPI from Hawkeye will tell you how fast a court is, and seen as though the courts have yet to be laid or played on in NYC, nobody can say how fast they are.

      It’s also tricky to discern anything from the CPI because there is no baseline measurement to judge it against or any real idea of how much 1 point in speed makes. So how much quicker is a 35 CPI vs a 36 CPI? It’s a pity there is no historical data to compare against.

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