One great shot in the box by American player (7,7)
I believe the answer is:
abraham lincoln
'one great shot' is the definition.
The definition and answer can be both people as well as being singular nouns.
Maybe there's an association between them I don't understand?
'in the box by american player' is the wordplay.
I cannot quite see how this works, but
'in' is within the answer.
'american' could be 'am' (abbreviation in some contexts) and 'am' is found within the answer.
This explanation may well be incorrect...
(Other definitions for abraham lincoln that I've seen before include "Famous American" , "president" , "fatally, he watched some play" .)