Old-fashioned cricket captain is two to four, say (6,4)

I believe the answer is:

square root

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'two to four say' is the definition.
I can't tell whether this defines the answer.

'old-fashioned cricket captain' is the wordplay.
'old fashioned' becomes 'square'.
'cricket captain' becomes 'root' (Joe Root MBE, English cricketer).
'square'+'root'='SQUARE ROOT'

'is' acts as a link.

Can you help me to learn more?

(Other definitions for square root that I've seen before include "Mathematical term" , "For one, one" , "2 of 4, perhaps" .)

I've seen this clue in The Daily Express.

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