The first day of the year-end championships focuses on the dark horses vying to challenge more familiar contenders for the last great prize of 2013.

Stanislas Wawrinka vs. Tomas Berdych (Group A)

Berdych has qualified for the World Tour Finals every year since 2010. In contrast, this will be Wawrinka’s inaugural appearance at the season finale.

Wawrinka leads the head-to-head in this matchup 7-5, having won two of the three matches that these two contested in 2013. Their last meeting came in the fourth round of the US Open, when Wawrinka won in four sets. On indoor hard courts, though, Berdych holds a 2-0 advantage.

Although he has amassed more points than Wawrinka in 2013, it would be hard to argue that Berdych has had the better season. Berdych has lost all three of his finals this year and failed to advance past the quarterfinals at any of the four majors.

Wawrinka’s 2013 has easily been his best year on Tour. In addition to reaching the finals in Madrid and the semifinals of the US Open, upsetting Andy Murray in the process, Wawrinka also claimed the title in Oeiras by overcoming Ferrer in the final. Wawrinka’s 2013 season will also be remembered for the epic five-set match that he played against Novak Djokovic in the Australian Open fourth round. Despite losing arguably the best match of the entire season, Wawrinka presented himself there as a force to be reckoned with.

In this matchup, the surface definitely favors Berdych. His effortless, smooth groundstrokes produce flat, penetrating shots that blaze through the court and past his opponents.

The main problem for Wawrinka in this matchup is that he is going to be provided with less time to take larger cuts at the ball. The Swiss No. 2’s favorite surface is clay, partly due to the fact that it gives him increased time to take bigger strikes at the ball. Berdych’s pace and the speed of the surface will reduce the time that Wawrinka has to excute his groundstrokes.

Two other things to watch in this matchup are how much Wawrinka maximizes the backhand-to-backhand exchanges and how much he minimizes his chip returns. Going from backhand to backhand on the baseline allows Wawrinka to play his more potent shot into Berdych’s less lethal side. As far as the return of serves go, in their Davis Cup match earlier this year, Wawrinka was relatively passive returning serve.  He chipped many serves back into play, on which Berdych immediately pounced. Wawrinka must be more aggressive on return to prevent his opponent from delivering a strong first strike.

Prediction: Berdych in two sets

Richard Gasquet vs. Juan Martin Del Potro (Group B)

The Frenchman, who grabbed the final World Tour Finals spot, is making his second appearance at this tournament. He previously qualified in 2007. This is Del Potro’s fourth appearance at the World Tour Finals, previously known as the Tennis Masters Cup. His best showing was in 2009, when he finished runner-up to Nikolay Davydenko.

Del Potro has not lost to Gasquet since 2007 and owns their head-to-head 5-1. Their last meeting came in the semifinals of Basel last year, which Del Potro won comfortably.

Following his second round loss at the US Open, the Argentine won Tokyo, reached the Shanghai final, won Basel, and reached the Paris quarterfinals. His only losses of this outstanding fall came against Djokovic and Roger Federer.

After his quarterfinal loss in Paris, Del Potro was robbed at the Gare du Nord in that city while heading to London. Among other things, he lost a rosary that was blessed by Pope Francis earlier this year. Whether or not this incident has an impact on Del Potro’s week remains to be seen.

Gasquet’s post-US Open schedule has been nothing short of hectic either. The World Tour Finals marks Gasquet’s seventh tournament following the US Open. He has not taken a week off since September 23. In this time, he has reached the semifinals of Bangkok and Beijing while claiming his third title of the season in Moscow.

Regarding tactics, Gasquet will spend most of the match in counterpunching mode. Del Potro’s fearsome groundstrokes and blistering power will be difficult for Gasquet to counteract. Gasquet’s forehand and backhand are both relatively long strokes, and against Del Potro’s pace his timing needs to be nearly perfect.

In addition, Gasquet loves to entrench himself far behind the baseline. Against Del Potro, this strategy will not likely succeed, for it results in striking many balls that sit up into Del Potro’s elevated strike zone. Gasquet needs to stand closer to the baseline and hit flatter and with more variety than he normally does. If he cannot, Del Potro will pound him into submission.

Prediction: Del Potro in two sets