Off-season is a period of reflecting on the season behind us and trying to predict the year ahead based on the information we currently have. Marine of Tennis Notebook poses five big questions for the upcoming 2013 season and tries to foresee what kind of an outcome we will have. Marine discusses the challenge ahead of Victoria Azarenka in the beginning of the year, Serena Williams' No.1 prospects, the young generation, etc.

1. Will Victoria Azarenka be able to keep it up in 2013?

WHY YES: 2012 was what you’d call a confidence-boosting year for Azarenka. She managed to come out of a shadow of her peers Caroline Wozniacki and Petra Kvitova and started her own dominance. Achieving success of such scale has surely opened many doors for her, so she may have enough spirit and motivation to repeat the same next year.

WHY NOT: Her great run at the start of 2012 means there will be a lot of pressure on Azarenka’s shoulders from the very beginning. She’ll start 2013 with four big titles to defend (Sydney, Australian Open, Doha, Indian Wells), which is a total of 4370 in terms of ranking points. Will be tough…

2. Will Serena Williams become the next No.1?

WHY YES: Williams still has the upper hand over other top players, especially on the grand stages. Also, she has become more consistent, so if there is nobody to challenge her, she could surpass Azarenka quite comfortably during the Australian Open series.

WHY NOT: In 2012 Williams played a lot more compared to the previous years, which gave her opponents more opportunities to face her and study her game. Compared with other top players her schedule is lighter, therefore, if she doesn't manage to stay consistent she simply might not have enough points to reach No.1.

3. Will the Top 20 welcome a new member from the young generation (21 and under)? Read more »

Agnieszka Radwanska was the protagonist in two longest matches of the 2012 WTA Championships. After defeating defending champion Petra Kvitova at the opening of the $4,900,000 tournament, the Pole toiled for three hours and 12 minutes before losing to Maria Sharapova 5-7 7-5 7-5 past 2 a.m. on Wednesday night, while today she ensured a semifinal clash with lethal Serena Williams, by working for three hours and 29 minutes to defeat first-time qualifier Sara Errani 6-7(6) 7-5 6-4. It is actually the longest best-of-three-set match in the year-end Championships ever! Read more »

Samantha Stosur stepped in as a replacement for ill defending champion Petra Kvitova, but was soon ushered out of the WTA Championships by Sara Errani, first-time qualifier, who lost to Maria Sharapova on Day 1, but has now earned her chance to fight for a spot in the semifinals. There will be a tough obstacle, though. Errani is 0-22 against Top 5 players and her next opponent in the White Group is world No.4 Agnieszka Radwanska.

Today Errani cruised to a 6-3 2-6 6-0 victory over Stosur, whose aggression paid off in the second set, but she failed to build up on the momentum and berried by a total of 49 unforced errors to Errani's 15 she lost the match, finalizing it with the seventh double fault. Their winners count was 44 for Stosur and 18 for Errani. It's interesting that Errani hit more aces than Stosur, although it is two aces to one.

Serena Williams and Maria Sharapova have certainly qualified for the prestigious semis, while the other two qualifiers will be determined in tomorrow's matches of Sara Errani vs. Agnieszka Radwanska (the second match on schedule) and Victoria Azarenka vs. Li Na (the third match on schedule). Friday's action opens with a match between Maria Sharapova and Samantha Stosur, but its outcome will not affect anything. (photo: © Neal Trousdale)

The third and last match of the first day action at the WTA Championships in Istanbul was a rematch of the 2012 French Open final between Maria Sharapova and Sara Errani and again Sharapova was victorious, with similar scoreline, 6-3 6-2.

After a slow start of the White Group match and the first four games lasting almost half an hour, Sharapova broke Errani to 4-2 and took control of the encounter, finishing it with 39 winners to Errani's 6, but also 26 unforced errors to Errani's 13.

Errani's season has been stunning with four singles titles, eight doubles titles (including Roland Garros and US Open), the singles final at Roland Garros and now her first ever participation at the WTA Championships. Not to mention that she's also competing in doubles, the only player in Istanbul to play in both fields. However, the Italian is yet to beat a Top 5 player in singles and after today's loss she's 0-22.

To sum up Day 1 in Istanbul, our winners are: Agnieszka Radwanska over Petra Kvitova, Serena Williams over Angelique Kerber and Maria Sharapova over Sara Errani. Tomorrow, Sharapova is also playing the third match of the schedule, against Agnieszka Radwanska. (photo: © Neal Trousdale)

On Sunday night, the official draw ceremony took place at the $4.9-million WTA Championships in Istanbul, dividing the eight players into two round-robin groups. Serena Williams is the only multiple champion at the year-end finale and is 35-5 against the rest of the field combined (9-1 this season), while Sara Errani is 4-23 and is the only one with a negative head-to-head record against all the three players in her group. Let's have a closer look at the draw.

RED GROUP: (1) Victoria Azarenka, (3) Serena Williams, (5) Angelique Kerber, (8) Li Na

World No.1 Victoria Azarenka is a leader in match wins this season with 67, she's also a title leader with six (tied with Serena Williams), and this fall she's been 13-0 in matches and 26-0 in sets. Serena is fifth in the list of match wins this season with 53, even though inactive this fall, and has a stunning 10-1 head-to-head record against Azarenka. Moreover, two Grand Slams and the Olympics are among Serena's six 2012 titles and three of the six she won without losing a set.  Read more »