Back in 2014, at the US Open, the final was unusual in that it was the first in years and years that didn't feature one of the Big Three of Tennis: Federer, Nadal or Djokovic. If Murray is included, making it the Big Four, the same is true of all Grand Slams (and I think Masters 1000 tournament) finals since too.
The interesting thing is that week, FiveThirtyEight published two articles, both of which concluded that the next generation of tennis players won't need to match Federer, Nadal or Djokovic's results to become a number one player, they'll just need to match Murray's results. That's because they won't have to meet three of the top five best players ever in the semi-finals of every big tournament.
"We concluded our earlier piece by saying the second line and del Potro should aspire to match Murray. That’s no small achievement — and it could be big enough to reach the No. 1 ranking he’ll probably never attain, because these younger players are less likely to have to contend with the likes of Federer and Nadal for the entirety of their careers."
This analysis turned out to be completely true, except that the first player to match Murray's level when the other Big Four players declined was... Murray himself.
And, of course, Murray did attain the number one ranking. But he did that only by being the last dominant member of the Big Four once the others began to decline. That he beat Djokovic in the last match of the entire season to retain the number one ranking was a nice touch.
All this to say: Djokovic just got knocked out of the Australian Open in the second round. Murray is likely going to be number one for the entire year.
I predict another Murray-Raonic final in Melbourne.