Age just a number for Nadal, Federer and Djokovic

Only a number until it isn’t.

Today's high-tech rackets can extend a competitive lifespan and have created a generation of boring baseline sluggers. If the old-style wooden rackets were mandated, tennis would be a much more dynamic and youthful sport, ironically, like it was in the McEnroe, Connors and Borg years.

Give the young guns like Nishikori a go.

JeffLee, if you like serve and volley type of tennis yes, but the reality is that tennis audiences did not like that anymore, so about 30 years ago or so they started making the surface and balls slower, and of course racquet technology also advanced. I don't think anybody would enjoy playing or watching low quality shots using heavy wooden racquets anymore. But it is true that people started thinking about new formats for tennis, shorter, more dynamic sets, etc. 4-5 hours matches are fun for die hard fans, but kind of too long for general audiences, and too demanding for players.

Fighto, Nishikori had his chance, he is 30 years old and plagued by injuries, hardly a young gun. You may keep an eye on young talents such as Jack Sinner, Brandon Nakashima, etc., and of course the already established Thiem, Medvedev, Zverev, etc.

Hunger, passion and discipline sets them apart. Sportspersons Rafael Nadal, Novak Djokovic, Roger Federer, Lionel Messi, and Cristiano Ronaldo are setting new records all the time. Indeed age is no bar for those skillful guys.

@timeon

"I don't think anybody would enjoy playing or watching low quality shots using heavy wooden racquets anymore." 

If you really believe that, then I suggest you watch link below, McEnroe and Connors and Wimbledon, 1982: Wood and steel on grass, and astoundingly dynamic gameplay that inspired the modern tennis boom. Today's scene just ain't inspiring anymore, especially now that Federer is about to exit.

https://www.youtube.com/watch?v=lApSrH3tWCk&t=306s&spfreload=10