There are two common methods in table tennis: single round robin and elimination. If these two methods are combined, it is called mixed system. The choice of competition mode depends on the competition purpose, venue, number of teams (people) and other conditions.
One, a single round robin is called a single round robin. This method can make the participating teams or athletes have the opportunity to participate in the competition, and can determine the names of the teams or athletes more accurately. However, the number of single round robin is large, the competition time is long, and more venues and equipment are needed, so the number of teams or people participating in single round robin should not be too large, otherwise group round robin should be adopted.
(1) Calculation method of single round robin ranking: According to the international competition rules, 2 points will be scored for winning a game, 1 point will be scored for losing a game, and 0 point will be scored for the games that have not been played or have not been finished. The ranking of the group will be determined according to the number of games won. If two or more teams in a group have the same score, they should be ranked according to the results of their corresponding games. First, the game scores obtained between them will be calculated, and then the number of times of a single game will be calculated as needed.
(2) Although the group round robin can correctly arrange the ranking of teams (or people), it is difficult to use because of the large number of teams (or people), which brings difficulties to the organization and management of the competition. In this case, group round robin can be used. The most commonly used arrangement method of group round robin is "snake arrangement", that is, the sequence numbers are arranged according to the strength of each team (usually according to the ranking of the last game). The smaller the serial number, the stronger the strength, on the contrary, the weaker the strength. When grouping, the strength of each group is required to be average, that is, the serial numbers of each group are added. On the basis of "snake arrangement", some ball games divide seed teams and non-seed teams into groups by lottery, that is, No.65438 +0-4 team (seed team) is fixed in No.65438 +0-4 group or enters No.65438 +0-4 group by lottery; Then the numbers 5- 8, 9- 12, 13- 16 are drawn into the 1-4 group respectively. However, after the end of the grouping period, the second stage of the competition should be added and all the rankings should be discharged. There are two common methods: 1. For example, in the first stage, each group is divided into four groups for group round robin, and in the second stage, the first place in each group is a group for single round robin, and1-4 is decided; The second place in each group is a group, and the fifth to eighth places are decided; And so on. 2. In the first stage, the cross race is divided into two groups for round robin. In the second stage, the top two players in each group will compete to decide the number of places such as champion, runner-up and runner-up. In this way, the 5th-8th places are decided by 3 or 4 people in each group. 5 or 6 people in each group cross to decide No.9-12; According to this push.
Second, the teams (or people) participating in the single elimination tournament will compete in the arranged order. The winner will enter the next round of competition, and the loser will be eliminated until the champion is decided, which is called the single elimination tournament. The number of single elimination matches is relatively small, which is conducive to arranging more players to participate in the competition in a short time. However, this method is unreasonable, incomplete and opportunistic, and some measures must be taken to overcome these defects in order to play its role in practical application.
(1) The number of digits selected should be a power of 2. The commonly used numbers and positions in the competition are 8, 16, 32, 64, 128, 256.
(2) detour If the number of participants is not equal to the number of times, but less than the number of times, that is, when the number of participants in the first round is less than the number of times, no athlete's ranking is called "bye" ranking.
(3) When the number of participants is slightly greater than the power of 2, the square of 2 with the closest number of participants is selected as the number of numbers, and a few participants "grab the number". Grab the number is to play a game at the same number position first, and the winner enters the number. The position of grabbing the number is the same as that of bye-bye, and "grabbing the number" is also a round.
(four) seeds (that is, strong players or excellent players)
1, setting the role of "seed" The method of setting "seed" players is to overcome the irrationality of single elimination. When drawing lots, the "seeds" are evenly distributed in each "area" so as to meet at last, and strive to ensure the rationality of determining the ranking of the competition.
2. The number of seeds The number of "seeds" is mainly determined according to the number of teams or participants. Generally, a seed is set for1/6- 12 of the number of participants, that is, 6-12 players on average; At the same time, the number of "seeds" should be a power of 2, such as 2, 4, 8, 16, etc. 3. The position of "seeds" should be arranged as follows: the first seed is arranged at the top of the upper half; The second seed should be arranged at the bottom of the lower half; The third and fourth seeds should be inserted at the bottom of the upper half and the top of the lower half respectively; The fifth to eighth seeds should enter the bottom of odd quarters and the top of even quarters respectively; If there are many seeds (9- 16), and so on (the seed position number can be found in the seed position table). In fact, the "seeds" of the knockout stage are evenly distributed in various "zones".