2015--all drama, right to the end

This is where memories are created - Congrats to @ARadwanska for winning the #WTAFinals pic.twitter.com/dkE7GsBsS3

— WTA Finals Singapore (@WTAFinalsSG) November 2, 2015

Every year is dramatic in the world of professional sports, and especially in the WTA, but this past season just seemed to be built around drama. Now that it's over, we're left with some familiar questions, but also with some new ones.

Some of the struggles were, unfortunately, ones we've seen before. Petra Kvitova was so exhausted in the early spring that she withdrew from both Indian Wells and Miami. Late in the summer, she would finally get a diagnosis--mononucleosis. But this illness is only the latest in a series; Kvitova, who suffers with asthma and has had repeated respiratory infections, is physically fragile. Nevertheless, she won three titles in 2015, made it to the final in Singapore, and ends the year ranked number 6 in the world.

Vika Azarenka, who is also physically fragile--but in a different way--once again had to deal with the foot injury that kept her off the tour for five months in 2014. The highlight of her season, one could argue, was her third round match against Angelique Kerber at the U.S. Open. This was a grueling contest, won by the former world number 1, in which Azarenka got to display her very best tennis.

Caroline Wozniacki, another former world number 1, took a step forward and a step back in 2015, showing us some aggressive play and then kind of fading away. Venus Williams, however, won three titles and put herself back into the top 10, proving--yet again--that you can never, ever count out a Williams sister.

Timea Bacsinszky and Caroline Garcia played in two finals in two weeks in Mexico. Bacsinszky own them both, and earned herself an additional title, the Queen of Mexico. The Swiss star, who also reached the semifinals of the French Open, ends the season ranked number 12 in the world.

The double Mexican final was unusual, but perhaps even odder was Anna Karolina Schmiedlova's personal battle against Italy. The Slovak with the killer backhand was in three finals this season, all against Italians. She lost the first one to Sara Errani, but won the next two, against Camila Giorgi and Errani, respectively.

Also this year, Teliana Periera made history by becoming the first Brazilian woman to win a tour title in over a quarter of a century. Periera won Bogota and then backed it up with a victory in her native country when she also won the event in Florianopolis.

Genie Bouchard, attempting to recover from a world-class slump, had some of the worst luck on the tour this year. She slipped on a wet floor in the locker room at the U.S. Open and sustained a concussion, which took her out of the tournament and ended her season because of recurring dizziness. The floor of the physio room had been mopped and was still wet and slippery when Bouchard entered the room. She has filed a negligence suit against the USTA.

Belinda Bencic and Karolina Pliskova continued to impress, though Pliskova continued to disappoint in the majors. She has yet to get beyond the third round of any major; however, her amazing Fed Cup performance at the end of the season may very well have set the tone for a whole new phase of the young Czech's career. She ends the season as number 11 in the world.

Bencic won both Eastbourne and the Rogers Cup. With the Toronto victory, she propelled herself out of the "rising star" category and into the category of "serious competitor" when she mowed down a field that included Genie Bouchard, Ana Ivanovic and Serena Williams. The spontaneous Swiss, who is only 18, reached the round of 16 at Wimbledon, and appears to have nowhere to go but up.

As for the rising stars--they were busy in 2015. Elina Svitolina, Daria Gavrilova, Lesia Tsurenko, Johanna Konta, Kiki Mladenovic (already a doubles star), Danka Kovinic, Madison Keys, and Daria Kasatkina provided us plenty of thrills all year long. In Istanbul, Svitolina and Gavrilova created a last-minute doubles team that entertained as much with humor and antics as it did with tennis. The pair, who had never before played together and came in as alternates, knocked out the top seeds and then won the tournament. One can only hope that these two will play more doubles together. Svitolina ended the season in the top 20 in singles.

It wasn't all about rising stars, though. Francesca Schiavone and Svetlana Kuznetsova, who dazzled the tennis world in 2009 with their brilliant four-hour, 44-minute Australian Open round of 16 match, did it again. The two clay court veterans met in the second round of the French Open and played for three hours and 49 minutes. Once again, Schiavone won (6-7 [13-11], 7-5, 10-8), and once again, the level of play from both women was stunning.

Maria Sharapova started her year by winning Brisbane and then reaching the final of the Australian Open, but she was defeated--yet again--by Serena Williams. Sharapova won Rome, then injured her leg in the spring, became ill, and didn't play much after Wimbledon. However, she won both of her rubbers in her first-ever Fed Cup final. Maria Sharapova is a warrior, wounded or otherwise, and has a good year even when she has misfortune. The Russian star ends 2015 as number 4 in the world.

Lucie--meet Potential. For those of us who have waited so long to see Lucie Safarova rise to her considerable potential, 2015 was as good a year as we thought it would be. Top on her list of accomplishments was getting to the final of the French Open, and beating defending champion Maria Sharapova on the way.

Perhaps the most surprising news of the year was that Sara Errani and Roberta Vinci ended their doubles relationship. The world's top-ranked team had won five majors and had attained a Career Slam. They were best friends. No one saw it coming.

And then there is the puzzle that is Simona Halep. Halep got her early season off to a roar by winning two premier titles--Dubai and Indian Wells--back to back. She tried for a third, but was knocked out of the semifinals in Miami. It looked for all the world like the Halepeno heat was turned on big-time for 2015--and who can argue with a finish of number 2 in the world?

The problem is that Halep's ranking looks a little better on paper than it does in "real (tennis) life" because she had letdowns in really, really big matches. It's nothing to be ashamed of to lose to Ekaterina Makarova in a major, but the Russian's 6-4, 6-0 defeat of Halep in the Australian Open quarterfinals was an example of Halep's just "not being present" during the competition. The Romanian later said that she was done in by stress.

Halep's brilliant performance in the 2014 French Open final gave hope that she would redeem herself in Paris, but instead, she was knocked out by the ever-dangerous Mirjana Lucic-Baroni in the second round. At Wimbledon, Jana Cepelova beat Halep in the first round. The Romanian did much better at the U.S. Open, taking out Vika Azarenka in the quarterfinals, but then losing to eventual champion Flavia Pennetta in the semifinals.

Despite what she often says about not feeling pressure, it's obvious that Halep feels a lot of pressure during her biggest matches. Halep recently announced that Darren Cahill will be her coach next season, and that's a plus because she had previously stated she would not work with anyone who was not Romanian. Losing that kind of rigidity is always a step in the right direction, regardless of whether the Cahill relationship works out.

Here are my personal top 10 2015 occurrences, in ascending order:

10. Talk about "Just Do It": Bethanie Mattek-Sands and Lucie Safarova had never played doubles together, but at the last minute, they entered the Australian Open as a team. Unseeded, Mattek-Sands and Safarova won the tournament, and then turned right around and won the French Open, too (Mattek-Sands also won the mixed doubles title, with Mike Bryan). The pair also won Stuttgart and Toronto, and were on their way to perhaps even greater accomplishments, but Mattek-Sands sustained an injury that forced the team to retire from the WTA Finals round robin.

9. Excusez-moi!: France played Fed Cup giant Italy in the opening round of 2015 Fed Cup competition. Not only is Italy a threatening team within Fed Cup circles--they led 2-0 at the end of the first day of play. France had never come back from a 0-2 deficit in the history of Fed Cup, but Captain Amelie Mauresmo didn't let that fact trouble her. On the second day of play, she substituted Kiki Mladenovic for Alize Cornet, and Mladenovic defeated Sara Errani, after which Caroline Garcia defeated Camila Giorgi. That left doubles, and Mladenovic (of that winning team, "Mladenovic and Anybody") and Garcia took out--of all people--Sara Errani and Roberta Vinci, and took them out in straight sets, producing Vinci's first-ever Fed Cup doubles loss. It was one of the most thrilling Fed Cup ties of recent times.

And guess who Italy has drawn in the opening round of next year's Fed Cup?

8. How do you like me now?: Angelique Kerber gave no warning that she was about to go on a major tear in 2015. But, after under-performing in a number of tournaments, the German won Charleston in style, having to fight off numerous opponents who were determined to upset her. She also had two injuries, but instead of taking a rest, she went straight to Stuttgart and won that, too. And in doing so, she issued defending champion Maria Sharapova her first-ever Stuttgart defeat. Kerber was just getting started. She won Birmingham, and then she won Stanford. Winning four premier titles on three different surfaces makes for an excellent season.

7. Lady of Spain: At the end of last season, some of us were wondering when Garbine Muguruza was going to settle down. I guess she showed us: The Spaniard has ended her year with a ranking of number 3 in the world. Muguruza, who reached the final at Wimbledon, also won Beijing. Muguruza reached the round of 16 at the Australian Open and the quarterfinals of the U.S. Open. And while she has won only two WTA singles titles, there's just something about Muguruza that says "inevitable." She had to take almost a year off because of injury, and she can still be inconsistent, but the 22-year-old has a kind of on- and off-court poise that just makes you feel confident about her. Playing doubles with Carla Suarez-Navarro has also been very good for Muguruza.

6. You should endorse these Czechs: They did it again. Those Fed Cup-loving Czechs won the big trophy yet again, and they did it by beating Russia in the final. Lucie Safarova wasn't available to play, and Russia brought along Maria Sharapova as their special weapon. No matter. With help from Petra Kvitova and an on-fire Barbora Strycova, Karolina Pliskova unexpectedly led the charge. The final went to a fifth rubber, and Pliskova and Strycova (in a brilliant performance both at the net and on the baseline)--after dropping the first set--went on to clinch the deal for their country.

5. Addio!: Flavia Pennetta, whom Women Who Serve acknowledges as the original Fighting Italian, retired from professional tennis in 2015. Pennetta's career spanned 15 years, during which she won 11 singles titles (including Indian Wells and the U.S. Open), 17 doubles titles (including the Australian Open), and the hearts of countless fans. I long ago named her the Queen of Fed Cup. A fierce Fed Cup competitor who was part of the "big four" who brought Italy so much glory, Pennetta retired with a 21-4 Fed Cup singles  record, and an overall record of 25-5.

4. Revenge of The Ninja: It wasn't that good a year for Aga Radwanska (aka The Ninja, aka Disco Ball)--that is, until the fourth quarter, when the tour's greatest shot-maker turned it all around. Radwanska, who likes the Asian swing a lot, won Tokyo, then won the international tournament in Tianjin--her first two titles of 2015. The biggest was yet to come. Radwanska didn't think she was going to qualify for the WTA Finals, but these late-season victories got her into the top 8. However, once in Singapore, she went down 1-2 in round robin play.

Nevertheless, given the odd circumstances of an already sometimes puzzling event, the world number 5 made it to the final, in which she beat Petra Kvitova. No one saw it coming, including Radwanska, whose jaw-dropping trick shots and "how did she do that?" shots were on display constantly throughout the week in Singapore. What a treat to see that kind of talent rewarded with such a big title.

3. Perfezioni!: You are about to retire from a sport you love and to which you have given so much for so long. Your record of accomplishments is a thing of beauty, and you are beloved by fans and peers. What more could you ask for? Well, if you're Flavia Pennetta, on your way out, you could drop by Flushing Meadows and win the U.S. Open. Pennetta became the first Italian woman to win the Open, and the player who performed in the most majors (49) before finally winning one. She had to beat friend and countrywoman Roberta Vinci in the final, which only added to the drama. Prior to that match, Pennetta took out both Petra Kvitova and Simona Halep. What a way to leave the tour!

2. It was the best of times, it was the worst of times: World number 1 Serena Williams won the Australian Open, the French Open and Wimbledon. She needed one more win, the U.S. Open, to achieve the Grand Slam, one of the few accomplishments missing from her career. It wasn't the smoothest path for Williams, but she made it to the semifinals, defeating sister Venus in the process. And then--with just two matches to go--the much-anticipated historical occasion became something quite different than what people were expecting.

Williams lost to Roberta Vinci, who was unseeded for the first time since 2010. Fans were stunned, the press was stunned. Suddenly, there was history alright, but it was about having two Italians in the final, and not about a Grand Slam. The upset was huge, and Williams ended her season shortly thereafter.

1. Show me how you Santina!: With the demise of Errani and Vinci as the dominating doubles team, in stepped Martina Hingis and her latest partner, Sania Mirza. The very idea of Hingis playing with the Forehand of Fire was kind of exciting (the Hingis-Pennetta pair-up was a very good one, but apparently, it wasn't quite was Hingis was looking for). The competition was keen. Both the new and very successful pairing of Bethanie Mattek-Sands with Lucie Safarova and the established Russian team of Elena Vesnina and Ekaterina Makarova were on the rise.

Hingis and Mirza entered Indian Wells just a couple of weeks after they began practicing together. They won the title, then went to Miami and won that, too. But winning two premier titles back to back wasn't enough for them. They went straight from Miami to Charleston and won that title, too. At that point, Mirza became the first Indian woman to hold the rank of world number 1 in doubles. Mirza's singles career was ended by multiple wrist injuries and surgeries, but fortunately, that amazing, wristy forehand is still on display, and it's as deadly as ever.

Santina would go on to win Wimbledon and the U.S. Open, then three titles in the Asian swing, and also the WTA Finals. In the meantime, Hingis and Leander Paes won the mixed doubles titles at the Australian Open, Wimbledon and the U.S. Open. It's not a stretch to believe that a Career Slam is in the making.