| Tournament | Round | Trevor Halsall | Olga Visser |
| 15.04.1998 Australian Championships (TAS) | 5 | 424 | 370 |
| 01.10.2001 New South Wales Championships (NSW) | 10 | 380 | 335 |
| 25.01.2004 City of Sydney International Masters (NSW) | 3 | 467 | 302 |
| 12.04.2004 Australian Championships (ACT) | 17 | 391 | 370 |
| 26.01.2008 SYDNEY INTERNL MASTERS (NSW) | 6 | 443 | 371 |
| 04.05.2008 Queensland Championships (QLD) | 4 | 501 | 391 |
| 04.10.2008 NSW CHAMPIONSHIPS 08 (NSW) | 5 | 499 | 319 |
| Head-to-head after 7 games | 7 | 0 | |
| Average score | 443.57 | 351.14 | |
| Spread: | 647 | -647 | |