Well after you select your team, in the "tonight's matchup" screen press Y 7 times and on the seventh you hold Y and B and Up all at the same time till tip off. This gives you unlimited fire. Also, to do power up Dunks you press b 13 times and hold like above while you are rotating the D-Pad in a counter clockwise direction. This one is hard to do though because you dont have that much time there.