Explained method used between bridge partners (5)
I believe the answer is:
shown
'explained' is the definition.
(I've seen this before)
'method used between bridge partners' is the wordplay.
'method' becomes 'how' (I've seen this in another clue).
'used between' indicates putting letters inside.
'bridge partners' becomes 'sn' (North and South are team-mates in bridge).
'how' inserted into 'sn' is 'SHOWN'.
(Other definitions for shown that I've seen before include "Demonstrated" , "Displayed" , "Explained" , "Exhibited" .)