Agreed, but I'd put Heather McKay up there with The Don. https://en.wikipedia.org/wiki/Heather_McKay https://en.wikipedia.org/wiki/Heather_McKay > When she re

Agreed, but I'd put Heather McKay up there with The Don. https://en.wikipedia.org/wiki/Heather_McKay https://en.wikipedia.org/wiki/Heather_McKay > When she retired in 1981 at the age of 40, McKay had gone nearly 20 years undefeated (with the only two defeats to her name occurring at the beginning of her career). Interestingly, both come from Australia.