Who’s the best tennis player in the world? Most people would say Novak Djokovic. He’s just won a back-to-back Grand Slam sandwich with Cincinnati stuffed in between. Nole is absolutely blazing the biggest hot streak in tennis.

But Djokovic is not the best, according to the official rankings. Running on a 12-month cycle, the ATP point system puts him at number 3. It’s mathematically possible for Nole to recapture the top spot by the end of the year, but he needs some things to break his way.

A look at 5 key factors:

Rivals

Can Djokovic catch the 2 in front of him and fend off a challenge from anyone else? Current World Number 1 Rafael Nadal has amassed 8760 points, with Roger Federer at 6900 and Novak at 6445. Juan Martin Del Potro stands in 4th at 5980. Those are the only 4 players with a realistic mathematical shot at the year-end number 1. Delpo would have to crush at the final 2 Masters and the ATP World Tour Finals. Certainly possible, but he’s drained from an emotional loss to Djokovic in the US Open Final.

Novak Djokovic celebrates another US Open victory. (Adam Hunger/AP)

Both Rafa and Fed have loads of points to defend– and if they don’t win this year– they’ll drop. Remember late 2017: Rafa won Beijing. Roger won Basel. The two met in the finals of the Masters 1000 in Shanghai, which Fed won. That’s points galore right there. Win again, or lose them, boys. On the flipside, Novak sat out the entire end of 2017, so all he has to do this fall is grab his racquet and collect points. Any Tour match Nole plays is a net gain, as long as he wins. Rivals Factor: +

Court Speed

With a slightly more defensive style, some have suggested Djokovic got lucky at Wimbledon and the US Open this year with slower than normal court speeds. Milliseconds become valuable tools at the top levels of tennis, especially for a tactical surgeon like Novak. Slower courts on any given shot allows him more time to plan. That changes now. Shanghai has some of the fastest courts on the ATP Tour. Indoor courts like Paris and the O2 typically play fast. It not that Djokovic can’t handle it, but he’ll have to adjust. Court Speed Factor: –

Motivation

Does he even want to be number 1 again? For some players, it’s all about the Slams. Federer proved he wanted number 1 again. Earlier this year, he accepted a wild card at a small tournament in Rotterdam he had not played since 2013, just so he could swipe the top ranking from Nadal. Then Rafa got it back. Clearly those two care about the ranking. Consider this: Less than an hour after winning the US Open on Sunday, Djokovic was in the locker room discussing with his coaches how to improve his game even more. He’s hungry again. Motivation Factor: +

Calendar

Next Up: Djokovic and Federer will participate in the Laver Cup Sept. 21-23. That’s an event which gives no points. It’s wear-and-tear on the body and another date on the travel schedule, albeit a profitable one. On his website, Djokovic lists the Shanghai and Paris Masters, and he qualified for the World Tour Finals with his US Open win over Kei Nishikori in the semifinals. If for some reason Djokovic drops out of any of those events or doesn’t play well, it would be interesting to see if he picks up a smaller tournament to put him over the top the way Federer did. That would be an indication of just how much the ranking means to him. Calendar Factor: +

Roger Federer crashed out of the US Open in round four. Photo: Getty Images

Health

Since a rough spring when Djokovic admitted he came back from elbow surgery too soon, it’s been a remarkably steady return to form. His serve speeds are very close to what they were in 2016 when he dominated the sport, according to statistics from IBM. He’s also displaying his signature Gumby stretches and moving like the gazelle he’s always been. If you factor in that Nadal is hurt, and Roger is playing a limited schedule, health favors Novak. Health Factor: +

Conclusion: Djokovic should regain the top spot by the end of 2018. He’s come miles from where he was to start the year. If he takes over number 1, he can climb other mountains, like breaking the record for most Slams won. Or perhaps winning the Calendar Slam, a very distinct possibility in 2019.

Djokovic & The Number 1 Ranking: A Love Story

Times He’s Been Number 1 3
Last Time He Was Number 1 2016
Times He’s Finished The Year Number 1 2
Most Weeks At Number 1 223
Longest Consecutive Streak At Number 1 122