game was centered around her powerful serve and groundstokes. She hit her shots with relentless speed, power, and depth, and could generate sharp, acute angles with both her forehand and backhand. Her aggressive, high-risk playing style meant that she typically generated high numbers of both winners and unforced errors. Sharapova's greatest weapon was her backhand, which was described upon her retirement as "among the best in tennis". Her crosscourt backhand was her greatest shot, although she was also adept at hitting her backhand down-the-line; she was able to hit winners with her backhand from any position on the court. Her forehand was also strong, with her being capable of dominating opponents with her flat, powerful forehand. She was one of the few players on the WTA Tour who often used the reverse forehand, also known as the 'buggy whip' forehand; her forehand technique allowed her to hit winners from defensive positions. This shot excelled on fast grass, hard, and carpet courts; it has been speculated, however, that her reliance upon this shot may have contributed to her worsening shoulder injury. From 2010 onwards, when she returned after shoulder surgery, Sharapova began to hit her forehand with a more conventional swing, with increased amounts of topspin. This alteration allowed her to excel on clay courts, but affected her game on faster hard and grass courts. Instead of using a traditional volley or overhead smash, she preferred to hit powerful "swinging" volleys when approaching the net or attacking lobs. Later in her career, Sharapova added both a drop shot and a sliced backhand to her repertoire, making for a more unpredictable playing style; whilst her drop shot was highly telegraphed, her exceptional execution allowed her to end points, or induce unforced errors from opponents. Upon her return from her doping suspension, Sharapova began to attack the net more, and showed improved feel when volleying, being able to hit delicate volleys with increased regularity; this tactic was considered by some to compensate for her decreased power at the baseline as a result of her shoulder injury. Early in her career, Sharapova's first and second serves were regarded as powerful, and she was believed to possess one of the best deliveries on the WTA Tour. Since the beginning of 2007, however, problems with her shoulder reduced the effectiveness of her serve. Her shoulder injury resulted in not only inconsistent first serves, but also led