If the round robin rule is that nine teams are divided into two groups, how to calculate the ranking and number of times after a single round robin?

Six in group A and six in group B were drawn. Number the six teams.

Each group has six rounds of competition. In the arrangement of each group, the team is divided into two halves by the method of "fixed rotation". The upper part of the number is written on the left from bottom to top, and the lower part is written on the right from bottom to top, and then the relative numbers are connected by horizontal lines to become the team of the first round.

Table 1: fixed rotation arrangement method

Left 1-6

2——5

3-4 right

After the end of the second round, by fixing the number 1 on the left, rotate counterclockwise and discharge the rounds one by one.

Table 2: The second round should be

1——5

6——4

2——3

That is to say, relative to the table 1 and 1, 6 turns to 2, 5 pushes 6, 4 pushes 5, 3 pushes 4, 2 pushes 3. By analogy, in the next round, on the basis of Table 2, push 5 to the position of 6 and turn it counterclockwise. Rule out six rounds.