Beginner's luck

[Anh]

Test No. incompl/elem-6 "Start/Begin", question 7

I won a lot of money by betting on that horse but it was simply a case of ......... luck.

(a) start's
(b) starter's
(c) beginner's
(d) beginning's

Test No. incompl/elem-6 "Start/Begin", answer 7

I won a lot of money by betting on that horse but it was simply a case of beginner's luck.

Correct answer: (c) beginner's

Your answer was: incorrect
I won a lot of money by betting on that horse but it was simply a case of starter's luck.
_________________________

please kindly explain me the meaning of "beginner's luck"

[Torsten]

Beginner's luck is a term that describes the success which is achieved by an inexperienced person. In our case somebody who hadn't tried betting on horses before suddenly won a lot of money in the race.

TOEFL listening lectures: A university lecture by a Drama professor