Winning has its benefits. Just ask the Pistons.
  The atmosphere during practice Tuesday was loose, but serious, as the Pistons (3-1) prepared to face the Bulls tonight in Chicago.
  The Pistons' success, including a 100-78 victory over the Washington Wizards on Sunday, has been fueled by defense.
  "It's going to take this type of effort on defense every night," Cliff Robinson said.