With the clay season just beginning, what better time to take stock of the world No. 1s, Serena Williams and Novak Djokovic, who likely won’t have easy rides through perhaps the most taxing part of the year.

On Wednesday, Djokovic suffered a stunning loss to Jiri Vesely in the opening round of the Monte Carlo Masters. Djokovic was broken three times in the 2-hour, 6-minute affair, handing him his first loss (excluding his withdrawal in Dubai with an eye injury) of the season.

This sure isn’t the way he wanted to start the clay season. Still, the larger picture suggests Djokovic is the player to beat moving forward, unlike his WTA counterpart, Serena, who has not found a consistent groove all season.

With that, a look at where the respective top players in the world stand:

Serena Williams

She hasn’t won a title since last August. At age 34, I have my doubts whether she has another comeback left in her, which leads to this question: Will she be the No. 1-ranked player at year’s end?

If the early 2016 trends continue, then the answer is obviously no. For the first time in a number of years, we have a legitimate contender ready to overtake Serena. Victoria Azarenka enters the clay season coming off back-to-back titles in Indian Wells and Miami. She is motivated, fit and well-coached. Wim Fissette and Sascha Bajin take detailed notes — everything from patterns of play to technique and footwork to Azarenka’s emotions — every time Azarenka takes the court. Afterward, her team reviews these reports with great detail.

Azarenka’s transition game and forward-thinking approach is the best in women’s tennis right now. She has been brave with her second serves, even if it has meant double-faulting more often. I like that mentality. Poor second serves that get crushed by great returners is demoralizing. At least an aggressive second serve is something you control.

Azarenka plays with a strong intensity and maturity — but with a worldly perspective that was not there before. After missing so much time with injuries, Azarenka realizes her time to take control of the game is finite, and she’s taking advantage of this precious period.

As for Serena, she remains a staunch competitor, but we’ve seen her fold during the salient moments for quite some time now. Is it a loss of focus? Is the pressure of catching Steffi Graf’s mark off 22 majors — an Open era record — weighing on the American’s mind? As a professional player, these milestones can be distracting with so many eyeballs vetting every move.

And when you consider the points Serena has to defend now through September — and the lack of points Azarenka has to defend — it seems more than likely the world No. 1 ranking will change hands by the end of the year.

Continue reading on the next page about Novak Djokovic!