<h1>Coach changed Celtics' fortunes</h1> <h1></h1> </p> <h2>Assistant Thibodeau introduced defensive style which is the key to team's 20-2 start.</h2> <h4>Chris McCosky / The Detroit News</h4> AUBURN HILLS -- Which new acquisition has done more to change the culture of the Celtics this season -- Kevin Garnett or Ray Allen?</p> The answer, as great as both those stars have played alongside Paul Pierce, might be neither.</p> The day assistant Tom Thibodeau walked into the gym was the day the Celtics got serious about winning. Thibodeau is perhaps the premier defensive coach in the NBA. He has coached defenses for 17 seasons, 14 for teams that finished among the 10 stingiest in the league.</p> "What he does is, he makes you beat them from outside," said Pistons coach Flip Saunders, who brings his team to Boston for a 7 p.m. game Wednesday. "They pack it in and take away the paint."</p> The Celtics are No. 1 in five defensive categories, including points allowed (86.5) and shooting percentage against (.413). That, more than any other factor, is why they are 20-2.</p> "Part of it is their offense has been so good that they've been able to set their defense," Saunders said. "They've been playing a lot in the half-court and controlled the tempo of most of their games."</p> That's part of the Pistons' formula, as well.</p> They are second in points allowed (91.2) and third in shooting percentage against (.436).</p> "The big key, though, that makes them such a good defensive team is they have a guy in Garnett who's probably the best guy in the league as far as defending pick-and-rolls," Saunders said.</p> They also have a long-armed point guard from Kentucky named Rajon Rondo who has wreaked havoc on opposing point guards.</p> "When you have a point guard who is great defensively like that, who can stop point guards from setting plays up, that's a great start to being a great defensive team," said Tayshaun Prince, another long-armed defender from Kentucky. "Then when you've got a great defender like KG who can alter shots and control the paint, you've got two major trademarks of a great defensive team."</p>
