Continuing our Indian Wells daily preview series, we separate the four favorites on Thursday into the punchers and the counterpunchers.  Or, in a more picturesque phrase, swords and shields.

Maria Sharapova Maria Sharapova of Russia pumps her fist following her victory over Dinara Safina of Russia during the BNP Paribas Open at the Indian Wells Tennis Garden on March 15, 2011 in Indian Wells, California.


Sharapova:  After an uncertain opening game against Safina, the 2006 champion sharpened her focus and methodically snuffed out any ray of hope that her former nemesis might have nurtured.  Even as she marched inexorably towards the quarterfinals, Sharapova continued to level her frosty glare before each serve and inspect each adverse call.  This mental relentlessness recalled her tenure at the peak of the game, when she played each point with the same single-minded intensity without regard to the scoreline.  Against a less notable but far more sprightly opponent, the Russian will need to maintain that level of concentration as well as the spine-tingling shot-making that characterized her 28 winners in the previous round.  The three-time major champion also altered her serving stance (although not her motion) before the tournament, and she generally has controlled that shot more effectively here than for much of her comeback.

In contrast to the less mobile Rezai and Safina, Peng possesses the agility to track down and Sharapova’s skidding rockets.  Like her compatriot Zheng, her low center of gravity enables her to retrieve them more comfortably than Maria’s statuesque Eastern European opponents.  Also like Zheng, however, Peng projects little power from the service notch and must hope to protect her second serve with a high first-serve percentage.  From their previous meetings emerge little useful evidence, for Sharapova’s victory came on red clay six years ago, while Peng upset an exhausted Russian a day after she battled Azarenka for three and a half hours.  Able to absorb the pace of Petrova and Li Na, the Chinese star certainly could capitalize upon an erratic afternoon from the 2006 champion.  But Sharapova will control her own destiny for better or for worse, just as this proud competitor prefers.

Del Potro:  Having equaled his best performance in the desert so far, the Argentine tower of power shares Sharapova’s capacity to hammer groundstrokes through even this exceptionally slow surface.  His comeback has accelerated with implausible speed from semifinals in San Jose and Memphis to a title in Delray Beach and four successive victories here.  Without the privilege of a bye, Del Potro nevertheless showed little sign of fatigue during a three-set victory over Ljubicic or a two-tiebreak triumph over Kohlschreiber, when he saved five successive set points.  Will his physical and mental exertions eventually weigh upon his lanky limbs, especially when he plays for the second straight day?  On the other hand, the rusty Argentine may benefit from an injury to projected opponent Tommy Robredo, who overcame a painful leg strain against Querrey on Wednesday.  The valiant Spaniard has dispatched both of the American Cinderellas in his section, eliminating not only Verdasco-killer Querrey but also Murray-killer Donald Young.  Should he dare to take the court, one suspects that the hunter will become the hunted, for Del Potro’s massive forehand has grown progressively more ominous from one victory to the next.

Rafael Nadal - BNP Paribas Open


Nadal:  Scarcely short of flawless in his first two victories, the world #1 displayed his mortal nature in a surprisingly complicated meeting with Indian qualifier Somdev Devvarman.  Since his draw nearly emptied of contenders within the first two rounds, Nadal could trace a tranquil route to the final.  Having slipped outside the top 200 with injuries and advancing age, Karlovic has risen from the catacombs of obscurity this week with victories over Ferrer, Simon, and Montanes.  Probably more remarkable than his unbroken sequence of service holds across eight sets was his ability to break his seeded opponents six times despite a normally woeful return game.  Nadal has likened returning the Croat’s serve to a soccer goalie receiving a kick in the stomach, and he has dropped sets to this intimidating opponent on more than one occasion.  Although the slow surface has denied Karlovic his customary avalanche of aces, he has found plentiful opportunities to stride to the net for a comfortably high volley.  Confronting the peerless passing shots of the Spaniard, that task grows significantly more difficult.  One could imagine Karlovic forcing a tiebreak or two, perhaps even slipping away a set with a little luck if Nadal fails to elevate his level from Wednesday.  When a match hinges upon a few key points, however, few players have a keener knack for capturing the moment than the world #1.

Wozniacki:  Seeking to tighten her grip upon the #1 ranking, last year’s finalist has become the clear favorite for the title following the early exodus of almost the entire top 10.  Alone among the other survivors is Wozniacki’s quarterfinal opponent, a close friend off the court and a fierce rival on it.  Perhaps as a result of their congenial relationship, their previous encounters have featured scintillating tennis only sporadically but have compensated for that flaw with dramatic suspense.  Last fall in Tokyo, for example, the world #1 thoroughly dominated Azarenka through a set and a half before the Belarussian awakened to play an inspired tiebreak and force a third set.  At that stage, Wozniacki rushed to a 5-0 lead, only to watch it nearly evaporate beneath her opponent’s assault.  Their rivalry looks likely to assume center stage after the current generation of WTA stars fade, mixing talent with glamor in the fusion beloved by the WTA’s marketing squad.

Diverging in personalities more than in playing styles, they arrived at this anticipated meeting only after rallying from one-set deficits in the previous round.  But he parallels between those comebacks stop at the surface.  Whereas Wozniacki progressively consolidated her control over a flagging Kleybanova and romped through the final set, Azarenka averted four match points against Radwanska during a match that lasted over three hours.  If the Belarussian has recovered physically from that ordeal, she may have gained psychological impetus through her brush with disaster.  Extremely fortunate to have remained in the desert for another round, she can attack her shots liberated from the tension of expectations.  In order to postpone a flight to Miami that looked imminent two days ago, however, Azarenka must curb her serving struggles and find a way to hold more comfortably than she did against Radwanska.  No serving leviathan, Wozniacki still maintains her equilibrium far more steadily than does her friend and can navigate through her service games more efficiently.  Azarenka can unveil her arguably greater potential only when she develops a similar ability.