Round robin rules
Analysis:
Round robin system means that each team can compete with other teams once or twice, and finally calculate the ranking according to the results. This kind of competition is reasonable, objective and fair, which is beneficial for teams to learn from each other and exchange experiences.
The round robin system includes three ways: single cycle, double cycle and grouping cycle.
single loop
Single cycle means that all participating teams can meet once, and finally rank according to the points and gains and losses of each team in all competitions. If there are not many teams and the time and venue are guaranteed, this kind of competition is usually adopted.
Calculation of the number of rounds in a single round-robin competition
If the number of teams is even, the number of rounds is the number of teams minus 1.
For example, if 8 teams participate in the competition, the number of rounds is 8- 1=7.
If the number of teams is odd, the number of rounds is equal to the number of teams.
For example, if five teams participate in the competition, it will take five rounds.
The purpose of calculating the number of rounds is to calculate the total time required for the game.
For example, there are seven participants in the competition, and the number of rounds is seven. If there is a two-day break in the middle of the game, the total time of the game is nine days.
Calculation of the number of single-cycle games
The formula for calculating the number of players in a single round-robin game is: x = n (n-1 )/2, that is, the number of players * (the number of players-1 )/2.
For example, 8 teams participate in the competition, and the total number of competitions is:
The purpose of calculating the number of games is to calculate the number of venues needed for the game, and then consider the number of referees and how to arrange the game schedule.
Arrangement of single round robin
Generally, the arrangement of single-cycle competition sequence adopts rotation method.
No matter whether the number of teams is even or odd, they should be arranged in even numbers. If it is an odd number, you can add a "0", and the team that meets a "0" will have a bye.
For example, there are 8 teams participating in the competition, as shown in table 1- 1. Chart display
This rotation method is suitable for teams that don't know each other's strength, so it is very likely that the strong teams will meet in advance by drawing lots and positioning.
"Counter-clockwise rotation", which can keep the final game exciting, is a common arrangement method (Table 1-2). Chart display
When there are five teams participating in the competition, they can be arranged by adding "0", as shown in Table 1-3. Chart display
The following methods can usually keep the final competition exciting, which are common arrangement methods, as shown in Table 1-4. Chart display
In order to avoid uneven work and rest, you can also put "0" in the lowest position on the far right and keep it still.
After the round-table meeting is arranged, each team draws lots, fills in the round-table meeting according to the number drawn by each team (or determines the number according to the ranking order of the last game), and then prepares the competition schedule. When compiling the competition schedule, we should first implement the principle of equal opportunity and fair competition, and of course, we should also take care of the needs of the competition (audience) appropriately. We can adjust the time (morning, afternoon, evening), venue (large or small pavilion), region (local or foreign) and other aspects to achieve a general balance between teams.
In the arrangement, the interval between rounds should be considered to ensure that athletes have enough rest time. If the competition cycle allows, you usually have to take a day off after three rounds. The color of the clothes should be implemented according to the rules, that is, the top team (home team) of the squadron in the order book should wear dark clothes. Pay attention to leaving time for washing and drying when finishing.
Table 1-5 is a more formal competition schedule format. Chart display
Domestic and international circulation
Double cycle means that all teams can meet twice, and finally rank according to the points and gain and loss rates of all teams in two cycles. If there are few teams or more competition opportunities, double-cycle competition is usually adopted.
At present, the national men's basketball League A adopts the home and away game system, and the first stage of the preliminaries and the 9~ 12 relegation game adopt the double round robin system.
The number of rounds, the number of games and the competition time of double round robin are all multiples of single round robin.
Grouping period
The grouping cycle is to divide all the participating teams into several groups for the first-stage preliminary contest, and then for the second-stage finals between the winning teams in each group, so as to determine the ranking below 1. In the group preliminaries, the single round robin system can be adopted, and in the finals, the single round robin system, the second namesake competition and the cross competition system can be adopted, so it is also called the mixed round robin system or the "two-stage system". Group cycle is suitable for competitions with many teams, and it can complete the competition tasks reasonably and fairly in a short time.
The disadvantage of grouping cycle is that if the teams are unevenly distributed due to different strengths, it may lead to the situation that the strong teams are laid off in advance and the weak teams rank first. In order to overcome this defect, a "seed team" should be set up in the arrangement. The so-called "seed team" is a team with relatively strong strength and achievements, which should be separated reasonably; The "seed team" can be determined through consultation or according to the ranking of the last competition. In order to take care of the organizers of the competition, it is sometimes stipulated in the competition regulations that it must be discussed and passed at a certain meeting.
The specific arrangement of grouping cycle is as follows:
For example, there are 16 people participating in the competition. In order to make the number of teams in each group even, it can be divided into 4 groups with 4 teams in each group. If time and funds permit, and you want to play more games, you can also divide into two groups, with 8 teams in each group. Divided into four groups, the "seed team" can be divided into four groups, eight groups, and drawn into the group, or 1, 8, 2, 7, 3, 6, 4, 5 (according to the ranking of the last competition).
In another serpentine arrangement, 1, 4, 5 and 8 "seed teams" are arranged in the first group, 2, 3, 6 and 7 "seed teams" are arranged in the second group, and other teams are drawn into this group.
If the single round robin system is adopted in the final of the second stage, 5-8 players will be decided by taking the first 1 of the four teams (the third and fourth of the two teams) as a group. The rest and so on, determine all the rankings.
In the second stage of the finals, if the second round with the same name is adopted, the runner-up of 1 in the two groups will win the championship, and the second runner-up in the two groups will win 3 to 4 places, and so on, and all the rankings will be determined.
In the final of the second stage, if a cross match is adopted, 1 in Group A will compete with the second place in Group B, and 1 in Group B will compete with the second place in Group A in the semi-finals. Then the winners of the two games will decide the champion and runner-up, and the losers will decide 3 or 4. The rest of the rankings are also conducted according to the above cross method. If two teams each have five teams, the remaining teams can't use cross-matches, and the final ranking can also be decided by the second match with the same name. This matter should be stipulated in the competition rules, as shown in table 1-6. The above situation should be emphasized in the hybrid system.