The key to the longevity of Novak Djokovic and Roger Federer is their willingness to constantly “listen, learn and improve every single day”, says the Serb’s coach Goran Ivanisevic.
Djokovic, 32, and Switzerland’s Federer meet for the 50th time in Thursday’s Australian Open semi-final.
Federer, 38, has not beaten Djokovic at a Grand Slam since 2012.
“Sometimes you think why the heck do you want to learn more? That’s why they – and Rafael Nadal – are the best,” Ivanisevic told BBC Radio 5 Live.
Defending champion Djokovic is going for a record-extending eighth title at Melbourne Park, while Federer is aiming to match his opponent’s current tally with a seventh victory.