But, while Djokovic and Murray have continued to dominate at the top of men's tennis, Federer and Nadal have seen their powers decline, with both hampered by injuries in recent times.
And Nadal now finds himself down in fifth in this week's edition of the rankings, having been overhauled by Kei Nishikori, with Federer staying in seventh.
Federer has not won an ATP title in 2016 and, though he reached the semi-finals of both the Australian Open and Wimbledon, missed the French Open and US Open through injury.
Nadal has fared slightly better, triumphing in the Monte Carlo Masters and Barcelona Open as well as in the Olympic doubles' final with Marc Lopez at Rio 2016.
However, the Spaniard has not reached the semi-finals of a grand slam since winning at Roland Garros in 2014 and did not go beyond the fourth round of a major this year.
Federer and Nadal had been in the top four since June 23 2003, two weeks before Federer won his first grand slam title.
Murray will look to close the gap on Djokovic in his bid to end the year as number one by following up his China Open success with victory at the Shanghai Masters. PLACE YOUR TEXT ADVERT BELOW:>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> How I Made Me =N=2.5 MILLION In 7 Days from 2 Common Product I Imported and how you can do the same. Click HERE FOR FREE Details right now Warning To Men: This 3 Foods Is Killing Your Erection. Click Here To Know Them Secret Fruits that increased my Manhood and makes me last 55 minutes+ all time - Click here to get it Warning: Got Arthritis? 3 Simple Ways To Get Cured And Be Permanently Free From Joint Pains. Click Here To See Them REVEALED!! Reduce Your Blood Sugar Level And Reverse Diabetics Within A Short Period Of Time. Click Here To See How MIDNIGHT,Pressed Mr Kilanko Suddenly Couldn't Urinate. Shrink your Enlarged Prostrate Here! Click Here Now