An American bowler for an English shire (5)

I believe the answer is:

derby

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'an american bowler' is the definition.
(I've seen this before)

I can't explain the rest of the clue.

(Other definitions for derby that I've seen before include "Local contest" , "close match?" , "Midlands city" , "20 horse 12" , "Classic horse-race" .)

I've seen this clue in the Evening Standard.

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