Because it is a single cycle system, there are several situations:

1. Three wins, 9 points.

2.2 wins 1 draw, 7 points.

3.2 win and one loss, 6 points

4. One win, two draws and five points

5. One win, two losses and three points

6. All three wars were defeated, 0 point.

7. One win, one draw and one loss, 4 points.

To sum up, it is impossible to get 8 points.

Thank you ~ ~ ~