目的：比較Djokovic在2010年與2011年面對Federer時在硬地球場接發球的回擊表現，包括回擊的方向落點（斜線、中間、直線）與回擊後的效果是否間接影響對抽表現的不同。方法：主要以探討Djokovic和Federer於2010年與2011年在硬地對戰表現比較研究，以接發球回擊表現為主要研究技術分析，再以描述性統計（descriptive analysis）進行分析。結果：Djokovic在右邊接發球區面對一發時回擊後直線比率由2010年的5.79%到2011年增加到12.66%；在左邊接發球面對一發回擊至有效區域的比率由2010年的11.67%增加到了2011年的23.81%。另外，整體回擊表現能在接發球後把對抽來回數量拉到三拍後的比率由2010年的16.34%增加到2011年的21%。結論：Djokovic在2011年能明顯降低對手在發球直接得分的機率，並迫使對手於每一分中增加來回擊球次數，進而提高本身取分的機會，Djokovic於2011年的接發球表現與2010年相較之下有顯著的進步。

This study aimed to determine to compare the placement, opposite angle, corporeality, straight of backstroke, and after effect of the counterpunch parameters between Novak Djokovic and Roger Federer, who participated in the games of in 2010 and 2011 on hard court. This study compared the skill of Djokovic and Federer as they competed in the rendition on hard court in 2010 and 2011. The most research analysis technique in this study was the backstroke of receive a service, which is the descriptive analysis. Novak Djokovic envisaged first serve at the receive a service region of the right side after backstroke. His straight intelligence quotient was increased from 5.79% in 2010 to 12.66% in 2011 at the receive a service region of the left side after backstroke to efficient range. The intelligence quotient increased from 11.67% in 2010 to 23.81% in 2011. Furthermore, the integer backstroke rendition after receive a service could exchange of drives back and forth, and the quantity dragged more than three shots. The quotient increased from 16.34% in 2010 to 21% in 2011. Djokovic could obviously decrease his opponent's direct acquired score opportunity after a serve. However, most of the times, he could merely counterpunch the mode of stabilization and increase the goal average. Djokovic can also inure and dominate the direction of backstroke at right and left side to receive a service region. This made exchange of drives to increase, and achieved the goal. The expression of receive a service for Djokovic had predominately improved in 2011 compared to 2010.