'Ullo again.
Let's ignore these third-rate Australians benchmark00 seems so dreadfully keen on but who don't fulfil the criteria of playing well in their limited oportunities but instead played well in a couple of their many opportunities while being pretty awful in the rest, and dig up some real examples. Jack Russell, for instance, who averaged 56.87 in his 10 Tests, and Cyril Walters, who averaged 52.26 in his 11.
No, that's not a mistake: it's the first Jack Russell, CAG Russell of Essex. Russell was one of those whose opportunities were rather badly restricted by Hobbs and Sutcliffe, and Walters retired early, at the age of 30. (Walters also had a f-c average of 30.75, and there aren't many players with Test averages 70% higher than their f-c averages.)
Cheers,
Mike