In discussions like this, I like to bring up Heather McKay. https://en.wikipedia.org/wiki/Heather_McKay https://en.wikipedia.org/wiki/Heather_McKay “She lost

In discussions like this, I like to bring up Heather McKay. https://en.wikipedia.org/wiki/Heather_McKay https://en.wikipedia.org/wiki/Heather_McKay “She lost only two matches in her entire career (in 1960 and 1962), and was unbeaten in competitive squash matches from 1962 through to 1981, when she retired”