6.3 Chile hosted an international football tournament. The local club, Cale-Cale, won the championship with 8 points, Dynamo from Moscow came in second with just 1 point less, Goiás from a Brazilian club took third place with 4 points, and Zvezda from the former Yugoslavia finished fourth, also with 4 points. How many more teams participated in the tournament and how many points did they each get?
[Solution] First, since the total score of the 4 teams is 23 points, there must have been at least 12 matches, thus at least 6 teams participated in the competition.

On the other hand, if there are $n \geqslant 7$ teams participating, then there would be $C_{n}^{2} \geqslant 21$ matches, with a total of $2 C_{n}^{2}$ points (each match results in a total of 2 points for the two teams). The average score per team would be $n-1 \geqslant 6$. However, the top 4 teams together scored 23 points, with an average score less than 6 points, which is a contradiction. Therefore, the number of teams participating in this competition must be 6.
With 6 teams participating, there are a total of 15 matches, resulting in a total of 30 points. Thus, the last two teams scored 7 points, which means the 5th place team must have scored 4 points, and the 6th place team scored 3 points.