Study On The Characteristics And Effects Of Coaches' Suspension In The 18th Women's Volleyball World Championships

This research regards 719 timeouts in 89 matches of the 2018 Volleyball Women's World Championship as the research object and analyzes related data comprehensively based on the scientific methods of document literature competition tape analysis,sample study,experts interview,and statistics.Perform a statistical analysis of the timing,reasons,and effects of the coach's request for a timeout,analyst the correlation between the effect of the timeout and the outcome of a competition.In addition,the difference between the value of the three-stage coach request for timeout and related indicators of the timeout effect was analyzed through statistical method.The results of this research are listed as follows:1.Research indicates that the most frequent request for a timeout is in the midfield stalemate phase,more than the sum of the start of the game and the key stages.However,in terms of the effect of timeout: the key phased > the midfield stalemate phase > the game start phase.2.The reasons for coach asking for a timeout are as follow: the number of Karen timeout is the same as other types,which is more than half of the number of the critical timeout.In terms of the efficiency of the timeout,the efficiency of the critical timeout is greater than the other two types.Among the direct effects of the coach's request for a Karen timeout,the attack on the 4th position in the first attack was the most,appearing 80 times in total,accounting for 52%.3.In the case of losing points before coach request for a timeout,the percentage of requests for a timeout is highest when the defensive is frustrated,accounting for 53%,the lowest percentage is only 7% when the offense is frustrating.And when the offense and defense are both frustrated,the percentage is 40%.When the defense is frustrated,the effect of timeout is the best and the effective suspension is 70%,of which the anti-reverse effect accounts for 33%.4.If the score is leading when the coach asks for a timeout,the percentage within 4 points lead is 79.4%.When the score is behind,the percentage of points difference between 3 to 7 points is 67%.In the overall timeouts,the percentage is highest when the points difference between 3 to 4 points,accounting for 30.5% of the total.The validtimeout had highly significant differences with invalid timeout when the points difference between 1 to 2 points and 3 to 4 points.And the timeout is the most efficient when the points difference is 1-4 points.5.Upon testing,an effective timeout may have no effect on the outcome of each match.However,the invalid timeout has a high degree of significance for each match.That is,an invalid timeout may have an effect on the outcome of each match.6.When the coach asks for a timeout,the percentage is about 9% when it caused opponents missed service.After the timeout,the percentage of first service scores will be 58%.7.Each of the top six matches has 4.54 more timeout than the preliminary,which is 2.86 more than the rematch.Compare the top six matches with preliminary and rematch,the effect of the first pass,round attack and causing opponent missed service after timeout is quite different.