The Boston Celtics are significantly better on defense with Kevin Garnett on the floor. The Celtics allow 94.6 points per 100 possessions when Garnett plays and 114.2 when he is on the bench. The 19.6 point gap runs the spectrum from a defense amongst the NBA's best to worst.
Even by using just the eyeball test, it's easy to see KG is still the defensive leader. He has lost a step, his defensive rebounding and blocks are down from his 2008 Defensive Player of the Year season in '08 but as Rasheed said "Ball Don't Lie" the numbers prove it, he's still THAT important to the Green.... Maybe even more important than ever before. Unless we come together defensively when KG takes a seat, we're without any paddles up that creak nobody wants to be on.