This has worked for me since the days of Lakers vs. Celtics on the Genesis, and it still works today with Live:
First, set up your def. matchups (use your best defender on the other guy's top scorer, high pressure on good players, low or med on the non offensive guys you know he won't use, NEVER auto dbl team)
Set up your plays to call either Full court press, half court trap, or man to man.
Always have box out on and crash boards either auto or off if you're getting beat by fast breaks
ALWAYS use the defensive player closest to the basket to block shots and get the boards or to take the charge i never guard the ball until it goes to the post or if the guy dribbles in for a layup. You'll get beat 8 outta 10 times if you do.
I use half court trap and man to man most of the time...maybe full court press a couple times...but you'll get beat by the long outlet by a good player
DON'T reach!

Just use your def slide stance and stay between the man and the bucket.
I usually hold the cpu and human opponents in the 30-40 % range. So, this has worked for me...give it a try