In the end, the Pittsburgh Steelers came up empty.

Not on the field _ they won their final three games to avoid a losing record, which seemed very possible after they inexplicably lost five in a row. Rather, they couldn't settle on an explanation for why a team that was so good for 1 1/2 seasons became so bad so quickly, a fatal flaw in a season filled with shortcomings.

In one of the most illogical seasons in their 77-year history, the Steelers (9-7) looked like champions again while starting 6-2. Then they suddenly forgot how to win _ losing to the Chiefs (4-12), Raiders (5-11) and Browns (5-11) amid the longest losing streak by any reigning Super Bowl champion.

They turned themselves around by beating the Packers (11-5), Ravens (9-7) and Dolphins (7-9), but it was too late by then to regain their grip on a season that had slipped away. They needed a combination of improbable scenarios Sunday to return to the playoffs for the fifth time in six seasons, and none occurred.

Take away only one of those dreadful losses to some of the NFL's worst teams, and they would be confidently striding into the playoffs with a three-game winning streak and the look of a team that no one would willingly choose to play in a win-or-go-home game in January.

"It's a shame, man," wide receiver Hines Ward said. "We're a good team."

How could it happen?

"I felt like we had our moments where we were unstoppable, we had moments we stopped ourselves and moments when the defense stopped us," Ben Roethlisberger said.

Maybe the quarterback is right: Nothing about the Steelers singularly was at fault, but everything was to blame during a season in which they played a far weaker schedule than they did while going 12-4 in 2008, yet finished with a much-worse record.

The defense that put together one of the best seasons in NFL history the year before looked old and overwhelmed at times. They were No. 5 overall, but plunged to No. 16 against the pass after leading the league in 2008.

If nothing else was consistent, at least this was: No lead was safe in the fourth quarter, when the Steelers lost five times after being ahead. They gave up a remarkable 135 points in the final quarter, the third most in the NFL, including a combined 43 points in successive home games against the Raiders (21 points) and Packers (22).

"That's something we have to correct," said linebacker LaMarr Woodley, who had a team-high 13 1/2 sacks.

A fast-aging defense in which nearly every key starter is 30 or older simply wasn't the same when safety Troy Polamalu, one of the league's best players, twice went down with left knee injuries.