hi
surely its all the diffrent parts added together that make up a powerful swing, without a firm stance and good posture and a good grip. a good wide arc, and timing and a down swing that starts with a small hip slid and turn, and the arms extending and the wrist uncocking at right point. impact with the club face square to the ball and on the sweet spot, any of the above not working would reduce power at impact and have negative affect on the flight of the ball.
bill