Research And Evaluation Of Libero’s Receiving Served-ball Skill And Defensive Effect Of Shanghai Men’s Volleyball Team

In volleyball games, the defender in the back who has flexiblepositions is known as a ‘‘libero’. Generally speaking, the inventionof ‘‘liberos’’ position brought the game of volleyball to anotherlevel, and greatly enhanced the popularity of volleyball. Since the‘‘liberos’’ usually performs better in receiving served-ball anddefensive plays compared to other players on the team, it helps to balancethe quality of defense among different teams. Better defense generatesmore back and forth of each play, thus it makes the game far morecompetitive and entertaining. In all,‘liberos’ position catalyzed thegame of volleyball to become more exciting and popular.Based on previous researches, despite the differences of methods, thecommon attribute of researching always comes down to the game statistics,including game plan execution, scoring percentage, turnover ratios andso on. These are all considered as the traditional analysis of gamestatistics which are easy to be perceived and analyzed. However the limitof traditional method is also obvious, it only provides a certainperspective of the game.This research mainly focused on50matches between top6teams in theNational Men’s Volleyball League from season2009to2012. Game videoswere analyzed by the ‘Data collection system of volleyball skills andtactics’ software.Through association pattern function of data miningmodule of the software, we got the descriptive statistics of skills ofreceiving serve ball and defense of Shanghai men’s volleyball team and‘liberos’ of their principal opponent. The conclusions are as follows:1The ‘liberos’ of Shanghai men’s volleyball team receives moreserved-balls than any other positions on the team, but due to poorperformance to get in the proper position there is no advantage whencompared with other teams in the league in this category.2there was a bigger proportion of ‘liberos’ in the defense play ofShanghai men’s volleyball team. The rate of successful receiving wasbetter than other teammates, and compare to ‘liberos’ of other teamsShanghai also had an advantage.3In different defensive plays,‘liberos’ of Shanghai men’s volleyballteam had a good performance at No.5defense spot, while on spot they failedto deliver same quality of defense.4In different defensive plays,‘liberos’ of Shanghai men’s volleyballteam had a better performance defending attacks from opponent No.4, No.1and No.6positions than defending attacks from No.2and3positions.5. Good receiving of served-ball in game could be a determining factorbetween winning and losing. In order to perform better in the game, theShanghai team should focus on practice by enhancing quality of each serveand the variety of serving ball.