抄録
The purpose of this research was to calculate the probability of winning a set in each score in volleyball game by rally point system. To achieve this purpose, following three procedures were taken.
1. All points in volleyball game was divided into the points of serving side and the points of serve receiving side, and those average point rates were calculated.
2. By the game simulation used those average point rates, the probability of winning a set in each score was calculated.
3. The values of actual victory probability in world cup '03 and '99 were compared with the values of simulation.
The main results obtained were as follows:
1. The average side-out point rates in world cup '03 were 69.3%(men) and 64.9%(women), and those values were almost equal in world cup '99.
2. As the result of simulation, it developed that the probability of winning a set becomes definite as the game goes to end of set even if differences in points are same.
3. Actual probabilities of winning a set in world cup '03 and '99 showed similar tendencies to the values of simulation. Concretely, the team which have three points lead at the score 20 for male (or having a four point lead at the score 20 for female) gained a set at 90% or more probability.
4. The table of probability of winning a set by simulation can widely use in game make or game analysis as a standard of victory probability in each level.
