Chance a version for testing (4)

I believe the answer is:

beta

'version for testing' is the definition.
(I've seen this in another clue)

'chance a' is the wordplay.
'chance' becomes 'bet' (I've seen this in other clues).
'bet'+'a'='BETA'

(Other definitions for beta that I've seen before include "Second highest grade of mark" , "software under test" , "less than perfect mark" , "Second Greek letter, B" , "final test" .)

I've seen this clue in The Times.

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