After making the playoffs for the first time in nine years and extending last spring’s opening-round series with the eventual NBA champion Celtics to seven games, the Atlanta Hawks appeared poised to take the next step by starting 6-0 this season.

Along with the Los Angeles Lakers, the Hawks were one of only two undefeated teams when the Celtics stuck them with their first loss on Nov. 12. Beginning with that loss in Boston, thanks to a last-second jumper by Paul Pierce in a 103-102 nail-biter, the Hawks have dropped their last four contests to fall to 6-4.

Maybe it was too soon to declare the fast-starting Hawks a top contender in the Eastern Conference, but veteran guards Mike Bibby and Joe Johnson have provided leadership and a little more than 40 points per game between them. The Hawks will be a tough test for opponents all season long if youngsters Josh Smith, Marvin Williams and Al Horford continue to develop into productive regulars.

The difference between the first six wins and the last four losses, however, has been Atlanta’s defensive game. Even in losing four in a row, the Hawks have averaged more points per game and generated higher shooting percentages, steals, turnovers and blocks than they did in claiming six straight victories.

Atlanta Hawks, First 6 Games vs. Last 4 Games, 2008

. . . . . . . . . . . . . . . 6-0. . . . . . .0-4
Pts/G. . . . . . . . . . . 98.8. . . . . .103.3
Opp Pts/G. . . . . . . .89.5. . . . . .112.5
FG%. . . . . . . . . . . . .448. . . . . . .453
3P%. . . . . . . . . . . . .395. . . . . . .478
FT%. . . . . . . . . . . . .701. . . . . . .761
Reb/G. . . . . . . . . . 44.7. . . . . . 34.3
TO/G. . . . . . . . . . .12.8. . . . . . 13.5
Stl/G. . . . . . . . . . . .6.2. . . . . . . 7.0
BS/G. . . . . . . . . . . .5.5. . . . . . . 6.0

After holding opponents to less than 90 points per game during their winning streak, the Hawks have allowed 112.5 points a game in their four losses.

“We haven’t been playing together, playing with any energy, like we were in those first six games,” said Johnson, the team’s leader with 25.9 points per game. “I think we’ve gotten real complacent and we haven’t been playing team basketball.”

Johnson didn’t mention team defense, but the numbers suggest much of that complacency has been guarding the basket. The Hawks have a chance to bounce back Wednesday night, when they face the 1-7 Washington Wizards. Only five teams are averaging fewer points per game than the Wizards (93.3), who are off to their worst start since 1999-2000.