Tennis Court surfaces and their speeds is a topic that often confuses people, there's a ton of conflicting information and a lot of speculation about whether a surface is playing fast or slow. But is there a way to end all that and simple say for example Indian Wells is played on X and it plays at X speed. In this post I'm going to try and find out.
Why am I writing this? Well for 2 reasons really, my last post asked whether or not Djokovic was unbeatable on Plexicushion, which is the surface used at the Australian Open. A couple of people mentioned that he's beatable on it because that's the surface used at the World Tour Finals, it's not actually so I thought it'd be good to clear up which surface is used at each tournament. And secondly, because the slowing of the courts is something that seems to be happening year on year so I want to know if court pace rating is a relevant measurement.
I'm going to look at all the surfaces in use at Grand Slam and Masters 1000 and 500 level, their official speed ratings designated by the ITF and the characteristics that each court has so there's no confusion about which surfaces are which and how quickly or slowly they should play according to the ITF. Remember that little bit.
What will I cover?
- The types of court surfaces
- How the ITF measures the speed of them
- The speed ratings of all Masters 1000, 500 and Grand Slam tennis courts
- Why I think the system is flawed (as I found out through doing the research)
- How I'd solve the court speed problem
What types of Court Surfaces are used across the world?
Tennis is probably one of the few games in the world that's 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:
- Artificial Clay
- Artificial Grass
- Other e.g. tiles, wood, canvas and modular systems.
Amongst those cateogies, there are 3-5 surfaces listed by the ITF who have been granted ITF status as an approved supplier.
How is the Speed of a Tennis Court Measured?
The most interesting thing about tennis courts are the speed of them and the ITF measure that with a system called Court Pace Rating or CPR for short. As we'll later find out, any court you see on TV or that's used for an ATP or Grand Slam 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 basically 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, which you can see in action below.
I won't go into the complexities of how it works, mainly because I don't have a clue 😉 but basically, the Sestée uses laser technology in its two boxes that are able to 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 is able to 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
Once the pace of the courts have 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|
If you want to read more about the surfaces and how speed is measured here's the technical centre on the the ITF website.
It's important to note that ITF Classification does not imply any form of ITF approval or endorsement. It's simply a rating system of the various surfaces they have approved as suitable for tennis. No weight is placed on different categories for preferred usage.
What are the Court Speeds for Masters 1000 & 500 tournaments and Grand Slams?
Tennis TV posted this interesting graphic. Please note this is a Court Pace Index and comes directly from Hawkeye data. So it's actually a true representation of the court speed for the speed of the court that year at each tournament.
CPI is calculated from the following:
- 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. CPI = court speed calculated from Hawkeye data from the main court during a Masters 1000 tournament.
Speeds in 2016
Speeds for 2017
A new graphic for 2016 and 2017 so far. The Australian Open is not listed here but it was rated at 40.
Court Pace Ratings for Each Surface from the ITF
Masters 1000 Tournaments
|Tournament||Surface||Court Pace Rating|
|Indian Wells||Plexipave IW||Category 1: Slow|
|Miami Masters||Laykold Cushion Plus System||Category 3: Medium|
|Monte Carlo Masters||Clay||Category 1: Slow|
|Madrid Masters||Clay||Category 1: Slow|
|Rome Masters||Clay||Category 1: Slow|
|Rogers Cup||Pro DecoTurf II||Category 4: Medium-Fast|
|Cincinnati||Pro DecoTurf II||Category 4: Medium-Fast|
|Shanghai Masters||DecoColor||Category 4: Medium-fast|
|Paris Masters||Greenset Grand Prix||Category 4: Medium-fast|
|ATP World Tour Finals||Greenset Grand Prix||Category 3 – Medium|
|Grand Slam||Surface||Court Pace Rating|
|Australian Open||Plexicushion Prestige||Category 4 – Medium-Fast|
|French Open||Clay||Category 1 – Slow|
|Wimbledon||Grass||Category 3 – Medium|
|US Open||Pro Decoturf II||Category 4 – Medium-Fast|
Masters 500 Tournaments
|Tournament||Surface||Court Pace Rating|
|Rotterdam||Greenset Grand Prix||Category 3 – Medium|
|Rio Open||Clay||Category 1 – Slow|
|Dubai||DecoTurf||Category 3 – Medium|
|Acapulco||Clay||Category 1 – Slow|
|Barcelona||Clay||Category 1 – Slow|
|Hamburg||Clay||Category 1 – Slow|
|Washington||DecoColor||Category 4: Medium-fast|
|Beijing||DecoTurf||Category 3 – Medium|
|Tokyo||DecoTurf||Category 3 – Medium|
|Basel||Greenset Grand Prix||Category 3 – Medium|
|Vienna||Rebound Ace Synpave||Category 2 – Medium-Slow|
|Valencia||Clay||Category 1 – Slow|
I've included the World Tour Finals in the Masters 1000 table, it uses Greenset which is also used in Basel and Paris. To complete the data it'd be nice to have the actual Court Pace Rating figure for each tournament, i.e Wimbledon CPR 38. But I've not been able to find those and they're not available 🙁
Why I think Court Pace Rating is Flawed
It's taken me a good few hours to compile all the information above and in that time I've realised that Court Pace Rating is flawed and that's down to four reasons:
- There's too much conflicting information from suppliers, tournaments and organisers. I don't think any of them know the true speed of the courts and have just put together a calculation/equation for the fun of it.
- The ITF isn't endorsing courts or recommending their usage they are just putting together a guide to aid people when purchasing a surface. So there's no rule to say for example the US Open must choose a Category 5 surface.
- Just because a court surface falls into a certain category on the day it's tested, doesn't mean the company who makes it can't change the manufacturing process to make it slower or faster at the discretion of the tournament it's being provided for.
- The balls make a ton of difference because some fly quicker, some fluff up more easily, some are heavier – there are too many variables. There are currently around 200 approved tennis balls on the ITF list.
1. Conflicting Information
When putting this post together I've read and found a lot of conflicting information that makes me think Court Pace Rating is nothing more than just the dream of someone behind a desk who thought it'd be a good idea to categorise court surfaces to help buyers but I don't think it really works.
Take for example the Indian Wells tournament, according to the ITF CPR ratings, Plexipave IW is a category 1 – slow surface but on the Plexipave website, the actual manufacturer, it states that Plexipave is a category 1 – slow surface. So which one is it? I don't think anyone really knows.
2. It's not an endorsement, just an aid
If you read the full details of court speed on the ITF website you'll see the quote that says:
A surface product included on the list of ITF Classified surfaces is classified purely on the basis of its Court Pace Rating. ITF Classification does not imply any form of ITF approval or endorsement
If there's no endorsement and it's just an aid then what is the point of it? I personally think there are too many manufacturers listed anyway.
3. It all boils down to the manufacturing process
Court Speed Rating only takes into account the speed measurement on a given day, there's no governing body or rulings that say the product has to be manufactured at that speed. And I'm not sure all the testing is done in situ. That almost renders them pointless in my eyes.
Let's say that I run the peRFect Masters 1000 tournament in England, I want to use Plexipave IW which is classed by the ITF as Slow, but I want it to be fast, not slow. I simply get the manufacturer to change the composition of the product i.e. make the finisher smoother, use more Rounded/Sub Angular particles so there's less friction and hey presto I have a court that plays like a Category 5. But wait, isn't Plexipave Category 1 according to the ITF? Let's not even go into the type of balls that I'm going to use, and how easily they fluff up because that affects things too!
Court Speed to me seems to be solely at the discretion of the tournament owners, the ATP and the sponsors, the CPR rating means very little.
That means that traditionally fast tournaments get slowed down even though they are using the same surface as always because they change the composition of it. If the owners want a Nadal/Djokovic final they make the surface rough and sticky so the ball bounces high and slows down. There's nothing to stop them doing it either which I find bizarre.
Take for example the US Open, they use Pro Decoturf II which is a category 4 -medium-fast surface, but is it? I'm not sure, this year it was widely reported they used more sand in the top coat to get more friction and slow the ball down. They also made Arthur Ashe slower than Armstrong, intentionally. So the CPR rating is simply a rating that provides no real value.
My advice – judge with what you see with your eyes, not what the ITF, ATP or tournaments tell you about the court surface. It's all smoke and mirrors.
4. The balls make all the difference
From what I can gather, the court pace tests aren't carried out with the balls in use at the tournament where the surface may be used. They're just tested with whatever balls are available that are on the ITF approved list. Like I said above, there are around 200 types of ball on the list, that can make all the difference.
Remember at the French Open in 2011 where they changed the balls so the flew through the air differently? The court didn't change but it played faster. Another variable and I think thee are too many balls in use, the number of approved balls should be limited.
If you look at Cricket there's only a handful of balls in use across the world and usually, each ball is specific to each country. E.g. in England they use a Dukes or a Readers and in Australia, they use a Kookaburra.
How to Solve the Court Speed Problem
My simple solution is that the speed of the court at any given tournament is predetermined by an outside body 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 DecoTurf mixture to make the surface rougher, it'd be made the exact 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. Allowing 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.
Not convinced the courts are getting slower?
You're not going to find anything more significant than that. And that's on grass, the supposed fastest surface!