In a second-round match against Philipp Kohlschreiber at the 2011 Cincinnati Masters, Roddick was given a penalty point, which resulted in a critical break of serve in favor of his opponent. The penalty point was given due to ball abuse, when Roddick smashed a ball into the stands in frustration after he had already been warned earlier in the match by umpire Carlos Bernardes for an episode of racquet abuse. This triggered another series of altercations with the umpire, with Roddick expressing his displeasure at the umpire's call. Roddick lost the match. At the 2011 China Open in Beijing, Roddick was asked by the Chinese press about his potential retirement, given his drop in the rankings. He recommended the reporter's retirement and left the session abruptly. Roddick is also known for his humorous on-court behavior and witty answers off-court in interviews and press conferences. He and Novak Djokovic are known for their player impersonations of Maria Sharapova, Rafael Nadal, Lleyton Hewitt and each other. Roddick was coached by Jimmy Connors, who was also known for his flamboyant personality during his playing career, for two years. Roddick used a discontinued version of the Babolat Pure Drive, extended to 27.5 inches. The racquet itself was heavily customised with additional weight placed in the head via the use of lead tape. The resulting racquet exhibits a more head heavy balance point and a higher swingweight than the stock model with a higher overall weight, though this is similar to the model he endorses at approximately 12 oz. Modifications of this sort are common for professional players. Roddick uses a modified version of Babolat's Pure Drive Roddick GT. The cortex in particular is visibly painted onto the racquet. The signature racquet designed for him by Babolat is slightly heavier (11.9 oz), stiffer (Babolat RDC index 72), and longer (27.5") than the standard Pure Drive Series (11.3 oz, Babolat RDC 71, 27"). The racquet is designed for a strong service due to its weight, stiffness, and length. According to Tennis Warehouse, it is the best one for this fundamental stroke. He strings with a custom hybrid (Pro Hurricane Tour + VS Touch(Natural Gut)). Roddick previously used Babolat RPM Blast and Babolat Revenge (used only for a short period of time) as his mains.