| Tournament | Round | Joan Colburt | Olga Visser |
| 03.05.1998 Maelstrom (QLD) | 6 | 451 | 293 |
| 17.05.1998 Southport Winter (QLD) | 6 | 339 | 406 |
| 11.10.1998 Greenbank (QLD) | 1 | 388 | 474 |
| 06.12.1998 Southport (QLD) | 6 | 444 | 377 |
| 02.05.1999 Maelstrom (QLD) | 5 | 362 | 441 |
| Head-to-head after 5 games | 2 | 3 | |
| Average score | 396.8 | 398.2 | |
| Spread: | -7 | 7 | |