G
GSMSampras
I'm not optimistic. In fact, I think 2019 will be his last year. If he resurges then he can go out strongly; if he continues to fade, he'll have to admit he's done winning big titles, which will see his interest collapse completely. I think the Australian Open will tell us a lot. Obviously with a resurgent Novak, Roger is unlikely to defend his title. But we'll at least have a sense of whether he can start the year strong and compete with the big boys.
2019 will be a dogfight with Novak and Rafa, with Novak pulling away. 2020 will see Novak reign over a cluster of rising Next Genners, with Rafa fading. 2021 will see Rafa retire and Novak fading. 2022 will be Novak's last year. That would see Roger retiring at age 38, and Rafa and Novak both retiring at age 35. Or so I see it. As a wise man once said, "Difficult to see; always in motion is the future."
There's no way Djokovic retires within one year of Nadal with such a superior serve-return combination.Federer will retire in 2020 at 39,Nadal in 2021 at 35 and Djokovic in 2024 at 37.