We know that Rafael Nadal will likely play against Novak Djokovic in the World Tour Finals, but the question now is when.
If Rafa finishes first in his group, he could meet Djokovic in the final, if he gets there by defeating the winner of a match between Roger Federer and Juan Martin del Potro (assuming that Djokovic reaches the final). If he finishes second, he will play Djokovic in the semifinal.
As per the rules of the tournament, the player that finishes first in the group plays against the player that finishes second in the opposite group. Here are the possible scenarios for Group A, Rafa’s group, now that Stanislas Wawrinka has defeated David Ferrer:
• If Rafa defeats Berdych then he will win the group and Wawrinka qualifies second.
• If Berdych beats Rafa in straight sets then Berdych wins the group and Nadal qualifies second.
• If Berdych beats Rafa in three sets then Rafa wins the group and Berdych qualifies second.
As you can see, if Rafa wins, Wawrinka is in. If not, there’s a chance we could see Rafa take on Novak Djokovic, who has already won Group B, in the semifinals. VAMOS RAFA!
Source: Beyond The Baseline