A historical examination of the evolution of tennis balls allows to conventionally identify three phases:
- An initial phase, in the early days of the game, when the first regulatory developments took place
- A second phase corresponding to the beginning of the Open Era, when regulations became more compliant to television needs because of tennis’s increase in popularity
- A third phase starting in 2015, when the industry embraced the ecological way of the reconversion of the production process of fuzzy balls.
Sources: Tennisplayer.net, Merchantoftennis.com, Stevegtennis.com, Udl.co.uk, Newyorktimes.com, Abnamro.nl
In the video above, shot in the 1920s, Renè Lacoste is about to try the first ball machine. It is possible to notice how balls are picked up from a carton box and not from a pressurized cylindrical metal tube, a packaging innovation which was introduced in 1926 by the American company Penn. A year before, in 1925, a new rule was devised, prescribing that balls had to bounce from 53 to 58 inches (135-147 cm), falling from a height of 100 inches. Bounce ranges have not changed, except for balls used at high altitudes and for special balls used by children for the progressive learning of shots.
At the onset of tennis, rubber balls were not pressurized. This way, there was no fear of losing pressure, because bounce and compression were produced by a rubber compound. However, the latter was far from being top quality, and consequently the balls were too tough or too soft or bouncing too low due to the lack of internal pressure. That’s why pressurization was introduced. But how were balls supposed to keep their bounce intact when they were simply packed in carton boxes? Before the advent of metal tubes, the solution was to over-pressurize the balls. This means that at the beginning of the season, balls were probably bouncier than at the end.
As for the use of felt, it is a material designed for tennis, provided with wider fiber threads than those used in clothing. This felt allows to:
- Reduce ball speed both after the impact with the racquet and in the air
- Improve ball control by preventing it to bounce irregularly after having hit the racquet
- Reduce ball bounce to a comfortable height, regardless of surfaces.
Felt is now the most expensive material of the production process.
TYPES OF BALLS
Today there are different types of tennis ball, which can be divided as follow:
- Type 1: fast, or known as regular duty (pressurized or not pressurized), commonly used on clay
- Type 2: medium, conventionally divided in Extra Duty for men and Regular Duty for women, commonly used on hardcourts
- Type 3: slow, commonly used on grass
- Balls to be used at high altitudes.
Additionally, other models have been created to facilitate the progressive learning of children (aged between 7 and 12) – it is the biggest innovation of tennis balls in recent years. The chart below summarizes the ITF standards that producers are required to abide by, with a few ulterior notes: Type 1 ball can be pressurized or pressureless, but the pressureless balls must have an internal pressure not exceeding 7 kPa (1 psi); Type 3 balls are also recommended for high-altitude play on any type of surface starting at 1.219 km above sea level; high-altitude balls are always pressurized and should only be used for play starting at 1.219 km above sea level.
| TYPES | MASS (WEIGHT) | SIZE | REBOUND | FORWARD DEFORMATION | RETURN DEFORMATION | COLOUR |
| TYPE 1 (FAST) | 56.0-59.4 gr. | 6.54-6.86 cm | 135-147 cm (53-58 in.) | 0.50-0.60 cm | 0.67-0.91 cm | White or Yellow |
| TYPE 2 (MEDIUM)1 | 56.0-59.4 gr. | 6.54-6.86 cm | 135-147 cm (53-58 in.) | 0.56-0.74 cm | 0.80-1.08 cm | White or Yellow |
| TYPE 3 (SLOW)2 | 56.0-59.4 gr. | 7.00-7.30 cm | 135-147 cm (53-58 in.) | 0.56-0.74 cm | 0.80-1.08 cm | White or Yellow |
| HIGH ALTITUDE (3) | 56.0-59.4 gr. | 6.54-6.86 cm | 122-135 cm (48-53 in.) | 0.56-0.74 cm | 0.80-1.08 cm | White or Yellow |
| Tolerance | 0,4 gr. | None | 4 cm | 0,08 cm | 0,10 cm | None |
| STAGE 3 (RED) FOAM | 25.0-43.0 gr. | 8.00-9.00 cm | 85-105 cm | None | None | Any |
| STAGE 3 (RED) STANDARD | 36.0-49.0 gr. | 7.00-8.00 cm | 90-105 cm | None | None | Red and Yellow, or Yellow with a Red dot |
| STAGE 2 (ORANGE) STANDARD | 36.0-46.9 gr. | 6.00-6.86 cm | 105-120 cm | 1.40-1.65 cm | None | Orange and Yellow, or Yellow with an Orange dot |
| STAGE 1 (GREEN) STANDARD | 47.0-51.5 gr. | 6.30-6.86 cm | 120-135 cm | 0.80-1.05 cm | None | Yellow with a Green dot |
Source: https://balls.com/rules/tennis- ball-specifications-defined-for-four-types.html
Research conducted in 2013 (and published in the “Journal of Sports Science and Medicine”) empirically showed that the forehand performance of a small group of eight children with an average age of 8.1 (±0,74) improved in a restricted court and with low-compression balls. The performance of the forehand hit from the baseline was evaluated using three indicators: speed and accuracy index (VP), speed and accuracy success index (VPS) and the percentage of success in hitting the shot – this last indicator is a function of the other two. Participants completed three different forehand patterns on two consecutive days, first using low compression balls on a 18,3 meters court and then using standards Type 2 balls on a 23,8 meters court. Participants using low-compression ball recorded higher VPS score values (p< 0,001) for each shot without errors, as well as higher VP (p= 0,01). The results are summed up below:
This research suggests that law-compression balls (as well as the reduced dimension of the court) facilitate the execution of the shot and improve children’s ability to hit with more speed and higher success rate. Performance improvement using such balls could become a decisive factor in the development of tennis fundamentals at a young age.
EVERY TOURNAMENT HAS AN OFFICIAL BALL
Managing to adapt to different balls in different tournaments is only one of the adjustments that pro tennis players have to make throughout the season. Some of them change the string tension according to the balls used in the various tournaments while also considering other (mostly meteorological) factors that might affect the bounce of the ball. It is known that heat makes rubber more elastic, thus making the balls bouncier. Humidity instead makes them heavier – this is the reason why Nadal is even more devastating at Roland Garros during sunnier days. What follows is the manufacturer used by each of the main ATP tournaments (Slams, Masters 1000 and ATP Finals):
Sources: essentiallysports.com, tennisfansite.com, ubitennis.com
Clay tournaments that sport Dunlop balls are Monte Carlo, Rome, Barcelona, Madrid, as well as the ATP 250 events that take place in Estoril, Munich, and Belgrade. Besides the above mentioned tournaments, Dunlop is the Official Ball of the ATP, a really important detail for merchandising purposes. Today, Dunlop is the most common ball brand in the tennis world.
Does balls supply represent a cost or an income from sponsorships for a tournament? Although figures are unclear, it is thought that the response depends on the importance of the tennis tournament. In December 2016, Le Figaro wrote that Wimbledon made the clever move of making its partners, including ball supplier Slazenger, the event’s official sponsors. This allows the AELTC to avoid restrictions imposed by brands other than the main suppliers and, at the same time, to have the necessary equipment while containing costs – revenues also grow because of the more collegial nature of the new partnership deals. In exchange for a sum negotiated by the two parties, brands can attach the Wimbledon logo on their products. Not all the tournaments have the importance and the contractual power of Wimbledon and this leads us to think that the less important the status of the tournament, the costlier supplies are.
Long-lasting supply collaborations imply that technological innovations are implemented by R&D departments of sponsoring companies, as is the case with Slazenger and Wilson. While Slazenger patented a phosphorescent fiber ball with a water-repellent system, Wilson tested different specific pressures only for balls used during the US open to reduce possible variations, as Bill Dillon (Wilson senior manager) told the New York Times in 2018.
Considering the chart at the beginning of this section (the one related to ITF standards for manufacturers), it can be noticed how rigid these standards are. However, there is some leeway when new balls come into play or at the end of the seven canonical games (in every match, balls are changed after the first seven games and then every nine games). This allows producers to stretch the limits a little bit. Jeff Ratkovich, Head-Penn’s senior business manager, claimed in the same New York Times article that pro players are able to “perceive even the smallest variation” – this is the reason why Head-Penn uses far more rigid specifications than those imposed by the ITF. When the changes of official supplies in the most important tournaments occur, players tend to be overtly critical. During the 2019 Championships, Nadal stated that balls had slowed down the game. During the Australian Open, a few months prior, Federer said that he had problems with the new Dunlop balls. During the 2011 Roland Garros, Djokovic, Federer and Murray complained about the new Babolat balls, which happened to make their debut in that edition of the event. In the autumn edition of the French Open held in 2020, Wilson balls made their debut, and as usual criticism abounded.
TOWARD THE ECOLOGICAL TRANSITION
On average, worn-out tennis balls are re-utilised for different purposes only in 3 to 7 percent of cases before they are incinerated and taken to a landfill – it is esteemed that about 300-325 million of tennis balls are produced every year. As early as August 2012, Ubitennis talked about a business initiative aiming to revitalize the old tennis balls, bringing them back to the appropriate pressure thanks to a special machine created by Rebounce. In 2015, this company teamed up with Advanced Polymer Technology and Ace Surfaces to create the Tennisballrecycling consortium, whose aim is to recycle the old balls to produce materials that will be used to re-surface tennis courts. How does the system work? After the first usage, balls are brought back to the appropriate pressure, extending their lifespan. When the felt is completely worn out, balls are snipped to recycle the rubber. Lastly, Laykold, an enterprise of the APT group (Advanced Polymer Technology) paves the tennis surfaces, recycling up to 10,000 balls for the surface of a single court.
The spring of 2020 marked the creation of Renewaball, a Dutch start-up which produces balls from recycled ones. Till then, the pure rubber and the felt partitions could not be separated – this was the main issue for the recycling process. The new start-up found out a way to do it, and therefore opened the door the production of a tennis ball that uses others as a base. The company has assured that the percentage of balls produced this way will significantly increase in years to come, but it has also warned that it will be impossible to produce a ball made of 100% recycled balls because the final product – a Type 2 ball valid for all playing surfaces and sold in pressurized plastic containers – will always need a minimum part of “pure rubber”.
Tennisballrecycling Vs Renewaball. Images courtesy of Tennisballrecycling and Renewaball
Nowadays, the production of tennis balls takes places almost solely in Southeast Asia, i.e. far from where tournaments are played. It has been calculated that a tennis ball can travel up to 80,000 km before it comes out of the box. This is a cost for our environment, which implies a lot of marine diesel, kerosene and CO2 emissions. As highlighted in the chart below, the majority of production takes places in Southeast Asia – Thailand is the first producer in the world of natural rubber, followed by China and the Philippines.
Moreover, the use of tennis balls produces thousands of plastic microparticles that the polyester/nylon felt releases into the air after a shot is hit. Those micro-particles will probably end up on the sea ocean or will be part of the floating plastic “soup” that is constantly increasing in the seas. The graphic below highlights the comparison of CO2 emissions between the traditional productive process and that implemented by Renewaball.
Overall, for each ball produced with the Renewaball productive process, there should be an impact reduction of 0,1764 kg Co2-eq per tennis ball. Considering that the Netherlands are currently using 5,5 million balls, this is equivalent to:
5,5 mil x 0,1764 kg Co2-eq = 970.200 (a decrease of KgCo2- eq per year)
Further details and clarification on the Renewaball productive process are available to the following link.
FINAL COMMENTS
Despite a productive know-how which is relatively stable over time, it appears that the market of tennis balls is going toward a monopoly. Until now, the most important takeover has been made by Head, which bought Penn in 1999. Reconversion of productive processes and the demand for new balls for children should guarantee other factors of differentiation, in addition to those crystallized over time due to specific sponsorship deals.
Once clarified the scenario, let’s try to imagine what the T7, the new tennis governance entity recently mentioned by Andrea Gaudenzi, might do vis-à-vis the implementation of a single supplier for tennis balls – albeit for different reasons, they would be following the supplying model of tires in motorsports (F1 and MotoGP). On the one hand, there is the undeniable advantage of having a single ball standard for all the players during the season. On the other, giving that much contractual power to a single interlocutor, representative of the various tennis organizations, seems unfeasible, given the number of interested parties that are currently part of this market, both in terms of tournaments and ball manufacturers. To get rid of sponsorship agreements, tournaments should receive more or equivalent incomes from the T7 or reduce supply costs. However, in the meantime producers will have developed specific know-how for playing surfaces, so another solution could be to split the supply cake on a triennial basis between the main manufacturers; however, this action could generate an oligopoly with fairly strong entry barriers for new producers. A final option would be to impose the use of balls from the same brand on each surface. If things remain unchanged, it is very likely that the entourages of the players will talk to experts in order to find algorithms able to optimise the string tension of racquets based on surface, ball typology, ball brand, the player’s feel and weather conditions, greatly simplifying the work of stringers.
As for the green solutions, the writer of this article thinks that the road undertaken by the producers aiming to extend the life of the balls without using plastic containers will only cause a reduction in sales and, besides, won’t solve the problem of their disposal. Tennisballrecycling’s solution is connected to the demand of new tennis courts to be paved and is thus connected to the sport – however, the destiny of said discontinued courts is still uncertain. The solution proposed by Renewaball, on the other hand, embraces logics and principles of circular economy, creating a potentially infinite productive cycle.
Article by Andrea Canella; translated by Luca Rossi; edited by Tommaso Villa
