Type of delivery members nail (3-4)
I believe the answer is:
leg spin
'type of delivery' is the definition.
(cricket term)
'members nail' is the wordplay.
'members' becomes 'legs' (leg is a kind of member).
'nail' becomes 'pin' (both can mean a sharp object).
'legs'+'pin'='LEG-SPIN'
(Other definitions for leg spin that I've seen before include "Style of bowling" , "What perhaps turns off" , "Type of bowling" , "Delivery method" , "Form of delivery" .)