I've gotten a lot of coaching violations, which I found unfair. But now that it's legalised, I'm more than happy I won't have to deal with referees that are so strict and want to kind of ruin the game."

The slugs are inserted into cavities in a heated compression press, where the rubber material cures into solid half-shells. Dunlop recently usurped Head’s ATP Tour ball as the officially branded orb of the men’s championship tour. The stark contrast between the two balls reflects the style of professional game the ATP wants to encourage. This ball plays fast, refuses to fluff up and is designed to be blasted for a winner time and time again. WTA spokeswoman Amy Binder told the Associated Press: external-link "The basis behind using the regular felt ball was that it limited the potential of arm, shoulder, elbow and wrist injuries. A hydraulic compression press heats the covered balls to cure the adhesive between the core and felt panels, creating a seam between the two felt panels and leaving a ridge formed by pinched felt.For me, it was a phenomenal feeling to look down and see the Wilson US Open ball in my hands. The fast nature of the ball helped me play my best tennis – I felt like I was in my comfort zone and gained confidence knowing that it suited my game very well. ” -Jonas Bjorkman This is something that we will continue to monitor and discuss further with both our athletes and our sports science teams." What about the coaching changes? How to get into tennis - it's fun, will keep you fit and caters for all levels and abilities. Find your nearest court and learn the basics today. I often find a new tube of Wilson US Open balls can last two matches at a time on a hard court before really starting to play any differently. If you play on carpet or artificial turf, they’d probably last even longer depending on how hard you slap them around. That durability is great to see from a top-tier brand, and even after their match quality is done, I find I can get a good couple of training sessions in with them before I need to retire them completely.

Meanwhile, American number one Jessica Pegula , who is part of the Women's Tennis Association's player council, said she was "personally not a huge fan" of the balls. She told The Guardian: "I feel like the first couple weeks there are a lot of double faults, because the balls are just kind of flying a bit more. I don't see why we couldn't switch to extra duty. But it's easier said than done, so hopefully the player council can work on that." With the spotlight on this disparity, there may well be a change at future US Opens, with the grand slam’s organisers, the United States Tennis Association (USTA), stating it “works closely” with the WTA and ATP Tours and their respective player councils “to determine what type of balls they recommend playing with for the coming US Open”. It clearly wasn’t a big issue for the world No 1 as she lifted the US Open trophy in impressive fashion last year, but the decision was made to change the balls for this year. Especially after three games of really hard playing, they are getting more and more light," she said at the Cincinnati Open last week.The US Tennis Association said "a number of factors" are considered in deciding which balls to use. Wilson also says that the regular duty balls are developed for softer surfaces, like clay or indoor courts, compared to the extra duty ones, which are for hard courts and "abrasive" surfaces. Wilson has given Tennis365 the inside story on how they put their US Open ball together, with 12 stages of evolution coming together to make the perfect US Open ball. Some women have issues with their arm playing with the heavier ball in the mixed doubles so it will be interesting to see how it works out now that everyone is using it in all competitions.

Tennis News Carlos Alcaraz admits he practises to beat Novak Djokovic as big goal remains on his mindWilson: The tennis ball goes through three different compression mould phases – the first to mould the half-shell, the second to mould and pressurize the core, and the third to adhere the felt. Selecting the felt is where a lot of the play characteristics come from. There is an incredible amount of technology that goes into the entire production process, from felt to core. Once we have a concept and have gone through the processes of making a tennis ball- we are continually testing – existing and new concepts – we are always trying to learn and improve.

The USTA have decided to use the same tennis ball for the men’s and women’s event at the US Open for the first time and we have been given the inside story on how the ball has been developed by manufacturers Wilson. I think people underestimate how mental and strategic the sport is, so they don't understand how big of a difference it is.

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I’m personally not a huge fan. I don’t see why we couldn’t switch to extra duty. I played with them when I’m at home or when I can’t find any balls. They just don’t fly as much. But it’s easier said than done, so hopefully the player council can work on that.” Pegula, however, has no issues with the men’s balls: “I played with them when I’m at home or when I can’t find any balls,” she said, shrugging. “They just don’t fly as much.”