The game changer would be they should be made of sustainable materials to also encourage juniors and those who cant afford new balls every few sets. I like anyone else love to play with new balls but most balls go bad after 6-8 games of use and always wondered why doesnt anyone make a new ball that lasts the same amount of time but are affordable to buy 2 to 1 ratios over the leading brands. All tennis balls have been proven to be toxic and the quantity worldwide that end up as landfill for used tennis balls is frightening. There should be a startup or tennis player that could do it for example Roger Federer could start the new RG balls with the help of Nike that could do it if he loves helping the poor and introduce tennis to 3rd world countries. Anyone doing so would be the first to market a sustainable rubber tennis ball or something along those lines maybe using recycled tyres pulverized and re-cast with a textured surface that gets rid of the fluff or cloned human hair so its affordable for all juniors in poor countries and any country really as Slazenger, Wilson and other long time branded balls are terrible, dont last, are toxic and too expensive for up and coming players to use more often. Even using some other fibre instead of acrylic would help. Tennis balls and car tyres are very big polluters worldwide.