Strategy needing map angle changed (4,4)
I believe the answer is:
game plan
'strategy' is the definition.
(game plan is a kind of strategy)
'map angle changed' is the wordplay.
'changed' indicates an anagram.
'map'+'angle'='mapangle'
'mapangle' is an anagram of 'GAME PLAN'.
'needing' is the link.
(Other definitions for game plan that I've seen before include "Strategy planned in advance" , "'Strategy worked out in advance (4,4)'" , "business strategy" , "Carefully thought-out strategy for achieving an objective" , "Strategy for winning as in sport" .)