The surprise, and it was a pleasant one, on the women’s side in 2013 was the resurgence of Jelena Jankovic at age 28. The former No. 1 and 2008 U.S. Open finalist jumped from No. 22 to No. 8 in the rankings, won a title in Bogota, lost to Serena Williams in the finals in Charleston and Beijing, and finished by pushing the world No. 1 to the limit in the semifinals of the WTA Championships. Not bad for a veteran player with a lot of mileage, and who relies on her speed. JJ hates being called a “veteran” so much, it seems, that she made everyone forget that that’s what  she is.

It won’t get easier, of course, as she approaches 30. But there are reasons to think that Jankovic can repeat her Top 10 performance in 2014. She played some of her best tennis at the end of the season, she’s one of the most natural movers and hitters on tour, and, despite her crankiness on court, she loves what she does.

Ad-In: Jankovic can play on all surfaces, but she was at her best last year on clay—she reached the quarterfinals at the French Open, and very nearly beat Sharapova in that match. Unlike Errani, she can hang with all of the top players, including Serena. I’d tell her to cut her schedule and concentrate on the big ones, but that’s not how JJ does things.

Ad-Out: About that loaded schedule I just mentioned... At 29, Jankovic may finally have to temper it. Speed is her game; if she starts to lose a little of it, she could struggle again.

As we approach the new year, we'll take a closer look at what's in store for the past year's top performers. To read more of our 2014 Season Previews, click here.