Each team ends a game (except the bye team), which is called the end of a round. The purpose of calculating the round robin is to plan the time or duration of the whole game, which is the main basis of the game schedule.
Its calculation method: Y= number of rounds, N= number of teams.
If the team is even, Y=N- 1, that is, the number of rounds = the number of teams-1.
If the number of teams is odd, then: number of rounds = number of teams.
Note: The number of rounds in double round robin is twice that in single round robin.
(2) The number of round robin matches
The number of round robin matches refers to the total number of matches completed by each team in turn. The purpose of calculating the total number of round robin matches is to plan and arrange manpower, material resources, competition schedule and venue.
The calculation method is as follows:
X=N×(N- 1)÷2 X is the number of matches, and n is the number of teams.
Number of single loop games = number of teams × (number of teams-1)÷2
Total number of double round robin matches = number of teams × (number of teams-1) (1) Arrangement method of single round robin matches.
1. Layout method of round table meeting
The arrangement method of rounds and sequences in a single round-robin competition is variable, and various regular rotation methods can be adopted. According to their own characteristics and needs, different events sometimes adopt special arrangement methods, and the change and transfer of competition order are varied. Generally, sum is a counter-clockwise rotation method: if the teams (or individuals) are even, this method is generally used to arrange the table for each round. If there are six teams participating in the competition, the first round of competition is to write the numbers 1, 2 and 3 on the left in turn from top to bottom, and then write the numbers 4, 5 and 6 on the right respectively corresponding to the numbers 3, 2 and 1, and then connect the two opposite numbers with horizontal lines, which is the first round of competition table (table 1). Fix the number 1 in the first round table, and rotate the other numbers counterclockwise by one position, which is the second round table, and so on. The advantage of this rotation method is that the closer to the competition, the closer the strength between teams, and the more intense the competition. There are other special rotation methods such as clockwise rotation method, "big rotation, small adjustment" method.
Table 1 Six teams in a single round robin: round one, round two, round three, round four and round five:1-51-41-31-22-56-45-34.
(1) lottery method for single round robin: after the rounds of single round robin are arranged according to the number of teams, the teams are arranged in the round table. There are two ways to arrange teams in the round table.
(1) draw lots. It is used when the strength of the participating teams is completely unknown, or when the rules of the game stipulate that lots must be drawn. The lottery is to make corresponding numbers according to the number of participating teams, and the teams with corresponding numbers will be seated accordingly and discharged into the round table.
② Take the ranking of last year's competition as the code for each team to enter the round table: for example, first place 1, second place 2, third place 3, and so on. In order to make the game reach a climax step by step, we should try to arrange the games with similar strength after the final round, and the ranking of each team can not be determined until the final round, so it is necessary to make appropriate adjustments to the rounds of the game. However, we should pay special attention to the following points: when adjusting the game, we must adjust the whole round together, that is, all the games in a certain round should be adjusted together with all the games in another round, and we must never adjust only one game in a certain round to another round.
(2) Arrange the competition schedule: After completing the round table, prepare the competition schedule (competition date, venue, etc.) for each round. ) and distributed to each group (Table 2).
Table 2 Competition Schedule: Arrangement Method of Double Round-robin Competition between Different Teams and Different Venues (2)
The round table arrangement of double round robin is the same as that of single round robin. As long as the first cycle is discharged, the second cycle can be repeated according to the table (Table 3), or the position can be re-drawn. How to conduct the second round of competition should be clearly stipulated in the competition rules. The number of rounds and events in double round robin is twice that in single round robin.
Table 3 Five teams participating in the two-wheel race 0-50-40-30-20-1-45-34-23-12-in the first round of five rounds.
The grouping cycle is usually divided into two stages: preliminary and final.
1. Early stage
According to the regulations, each team is divided into several groups, each group is arranged in a single cycle, and the group match table is discharged, and then the position of the seed team is determined. Generally, seeds are determined according to the number of groups or twice the number of groups. If the number of seeds is equal to the number of groups, the seed team will be arranged at the position of 1 in each group. If the number of seed teams is twice the number of groups, the "snake" arrangement should be adopted, and the seed teams should be arranged in each group 1 and 2 in turn. Seedless teams should also be positioned after drawing lots. Now, the drawing and "snake" arrangement methods of group single round robin are introduced as follows:
(1) 1. Seed teams are determined through consultation at the joint meeting: the number of seed teams is generally equal to the number of teams. If the game is divided into four groups, there should be four seed teams. In order to make the competition more reasonable, you can choose more seed teams, but they must be multiples of the number of groups. If the competition is divided into four groups, eight seed teams can be determined. The first seed team and the eighth seed team are grouped together; The second and seventh seed teams are grouped together, and so on.
(2) Method of drawing lots: The seed team draws lots to determine the grouping of each sub-team, and other teams draw lots to determine the grouping. For example, 20 teams are divided into 4 groups. Except for 8 seed teams, the remaining 12 teams will draw lots again. The lottery numbers are divided into four groups, with three identical lots in each group. Teams 12 draw lots to determine the groups, and then each team fills in the competition round tables of each group according to the groups. Another grouping method is snake arrangement grouping, that is, grouping according to the previous ranking. For example, when the 16 team is divided into 4 groups, the arrangement is shown in Table 4:
Table 4 16 teams are divided into 4 groups. Competition schedule groups 1, 2, 3 and 412348765 91012161514.
The ranking of each team in the preliminary round robin will determine its position in the final stage. Teams that meet in the preliminaries are still valid and will not participate in the finals. Commonly used competition methods include: the second namesake competition, sectional competition, cross competition, ranking competition, etc.
(1) homonym: those with the same ranking in each group's preliminaries are compiled together for competition. For example, in the preliminaries, the first place of the four groups is compiled into one group for a single round robin, and 1 ~ 4 people are decided. The second place of each group is compiled together to decide 5 ~ 8 people.
(2) Subdivision: Divide each group ranking into several sections, and group teams with the same ranking to determine the overall ranking. For example, 1 and 2 players of the two groups in the preliminary round are grouped to determine 1 ~ 4 players, and 3 and 4 players of the two groups are grouped to exclude 5 ~ 8 players.
(3) Cross-race: The top two players in each group cross-race, and the two winners compete for 1 and 2 in the final. The two losers compete with each other to decide 3 or 4 players, and each group of 3 or 4 players decides 5 to 8 players in the same way, and so on.
(4) Admission Ranking Competition: According to the admission ranking stipulated in the competition regulations, teams with equal admission numbers in each group will enter the finals (the number of teams participating in the second stage finals should be equal to or slightly higher than the number of teams with admission ranking). For example, there are 16 teams participating in the competition, and the top 8 teams are required to be admitted, and the preliminaries are divided into two groups. Then the top four teams in each group will enter the second stage finals, and the remaining teams will no longer compete.
(4) Matters needing attention in the round robin schedule
Round robin requires each team to compete with other teams. From the perspective of competition objects, participants are guaranteed equal opportunities, but there are still problems of unequal opportunities in competition order and conditions. For example, the time sequence of meeting with strong and weak opponents; How much physical strength each team consumes before the decisive battle between two teams with equal strength (referring to the unequal strength of opponents in the last game and the interval between halftime); The progress of each team is inconsistent; Advantages and disadvantages of site conditions and their adaptability to site conditions. It is impossible to achieve complete equality in all aspects, but it is necessary to minimize these unequal factors in the arrangement and make the whole competition achieve better results.
The following requirements and precautions are hereby put forward:
(1) When the team is odd, it is not appropriate to use the fixed counterclockwise rotation method of 1 team to arrange the competition order: at present, in all kinds of competitions at all levels, 1 team is fixed as the reference point, and other teams (or individuals) rotate one position in turn counterclockwise. The advantage of this arrangement is that it can ensure that two teams with equal strength will play in each round; No.65438 +0 seed strong team met the opponent who changed from weak to strong; In the final round, 1 was guaranteed to meet the top two teams of No.2, and the game reached its climax. However, this arrangement will cause one of the teams to meet the last round of bye teams many times in a row, causing the team to wait and rest. If there are seven teams, Team No.6 will compete with the team that had a bye in the last round in the last four rounds (Table 5), which is physically unfair to Team No.6.. The way to overcome this unreasonable phenomenon is to rotate clockwise, or to fix the "0" team in the upper right corner without rotating, and other teams can rotate counterclockwise.
Table 5 Rotation table of the first round, the second round, the third round, the fourth round, the sixth round and the seventh round1-01-61-51-41-3 65438-58 Otherwise, it will cause the unequal rest time of the competition teams, and may also provide an "opportunity" that can be used to interfere with the results of the competition.
(3) Note that the rest time of each team is basically equal after each game: the minimum rest time of each team in different sports is different. Among them, the interval between football breaks is the longest; Volleyball, basketball, handball and so on. Follow; Table tennis and other small ball events have a short time. When arranging, we should pay attention to ensuring the intermission time of each team, try to get the two sides close to each other and prevent unequal treatment when restoring physical strength.
(4) Match conditions, venues, spectators and time should be balanced, so that each team can basically reach a balance; When arranging the schedule, we should push the game to a climax step by step, and the number of games in each round should be kept even, so as not to make the game cold and make it more tense. The determination of single cycle sorting should be carried out according to the following steps:
1. The ranking is determined according to the points, and the one with more points ranks first. The score is 2 points for winning a game, 0 points for losing a game 1 point, and 0 points cannot be completed without playing a game.
2. If two or more teams (people) have the same points, their rankings will be determined according to the results of their competitions. First, calculate the points obtained between them, and then calculate the winning-losing ratio, the number of games and the points of a team's game (team game) as needed until it is counted as a famous game. Game ratio = number of wins/losses; Game ratio = number of wins/losses; Score ratio = winning points/negative points.
3. If the ranking of one or more players has been decided at any stage, but other players still have the same points, in order to calculate the ranking of the players with the same points, the competition results of the players who have decided to become famous should be deleted when the calculation continues according to the above procedures.
4. If the ranking of some teams (people) cannot be determined according to the procedure specified in Article 3 above, the ranking of these teams (people) shall be determined by drawing lots.