Points are calculated based on:
9 darts: 15 points, 10 darts: 9 points, 11 darts: 8 points, 12 darts: 7 points, 13 darts: 6 points, 14 darts: 5 points, 15 darts: 4 points, 16 darts: 3 points, 17 darts: 2 points, 18 darts: 1 point