| Tournament | Round | Ethel Collins | Ivor Zetler |
| 25.01.1998 City of Sydney International Masters (NSW) | 14 | 305 | 375 |
| 25.01.1998 City of Sydney International Masters (NSW) | 15 | 332 | 373 |
| 25.01.1998 City of Sydney International Masters (NSW) | 16 | 395 | 300 |
| 05.04.1999 Australian Championships (NSW) | 1 | 355 | 429 |
| Head-to-head after 4 games | 1 | 3 | |
| Average score | 346.75 | 369.25 | |
| Spread: | -90 | 90 | |