A.J. Smith, the Chargers’ GM and former Hendricken High football player, was criticized early in the season when his team was struggling.

Sean M. Haffey / San Diego Union-Tribune

A.J. Smith would be the first to acknowledge that the Chargers got lucky.

“We got exactly what we needed — a monumental collapse by the Denver Broncos,” said the San Diego GM, who grew up in Cranston and played high school football at Bishop Hendricken.

With four games left in the season, the Chargers were 4-8. With three games to go, they were 5-8 and the Broncos were 8-5. One win by Denver, or one San Diego loss, and the Broncos would win the AFC West.

“We had messed up,” Smith said. “We were three games back with three to go, and everybody was saying we weren’t going to make the playoffs. But what could we do? We couldn’t sit back and feel sorry for ourselves.

“We weren’t playing very well, but I knew we had a bunch of guys who wouldn’t let go of the rope. Our theme, down the stretch, was to keep winning and keep hoping. If we had lost a game, and then found out Denver had lost, too, we would have been sick. We just kept winning. And the Broncos kept losing.”

In Week 15, while the Broncos were losing at Carolina, the Chargers were pulling out a miracle win at Kansas City, scoring two touchdowns in the final 73 seconds to nip the Chiefs, 22-21.

The following week, the Chargers contributed to Tampa Bay’s late-season slide that would cost the Bucs a playoff spot, rolling to a 41-24 victory on the road.

“When we found out on the flight back to San Diego that Buffalo had won at Denver, all hell broke loose on the plane,” Smith said. “That meant we had a winner-take-all game at our place against the Broncos.”

The Chargers took it to the overmatched Broncos, putting a 52-21 pasting on Denver that gave San Diego the division title and cost Mike Shanahan, the Broncos’ longtime — and two-time Super Bowl-winning — coach, his job.

Of course, when the Chargers were 4-8, there was no shortage of people saying that San Diego coach Norv Turner should be fired, along with the guy who had gotten rid of Marty Schottenheimer in order to hire him — Smith.

That was when Smith recalled something he was told by Marv Levy, who won four straight AFC championships in Buffalo, where Smith was first an assistant director of college scouting, and later, director of pro personnel.

“Marv told me when I was hired (as GM of the Chargers) to always do what I thought was right,” Smith said. “He said: ‘No matter what you do, some people are going to like you and some people aren’t. If you win, people will think you’re bright and smart. If you lose, they’ll think you’re stupid and incompetent.’

“Marv laughed when he said, it,” Smith recalled. “But he was speaking the truth.”

Among the reasons Smith brought in Turner to replace Schottenheimer was that he believed Turner would be a much better coach in the postseason. Despite Schottenheimer’s impressive record in San Diego during the regular season, he was 0-2 in the postseason. He also had lost his last three playoff games when he coaching in Kansas City, and has an overall mark of 5-13 in the postseason.

With San Diego’s overtime win last weekend over the Colts, Turner is 3-1 in the playoffs as coach of the Chargers, tying him with Don Coryell and Bobby Ross for the most postseason victories in franchise history.

“Our record may have looked [bad] at 8-8,” Smith said, “but it really doesn’t matter if we were 14-2. Our goal — and I’ve said this a million times — is to win the division, get into the playoffs, and be playing our best football the last three or four weeks of the season.”

The Chargers have achieved that goal.

Now, they’ll take on the AFC North champion Steelers this afternoon in Pittsburgh in hopes of reaching the conference championship game for the second straight season.

They lost to the Patriots last year in Foxboro, 21-12. To get there, they had to upset the defending Super Bowl champion Colts in Indianapolis. The Chargers, who lost at Pittsburgh two months ago, 11-10, are underdogs again this afternoon — especially with standout running back LaDanian Tomlinson out of action, and all-pro tight end Antonio Gates hobbling.

Of course, just about everyone was counting out the Chargers when they were three games down in the division title race with three to go.

San Diego also is a better team than the record would indicate. The Chargers lost at Denver the second week of the season on a horrible call by the referee. They lost their opener to Carolina on a last-second pass. They had that one-point loss at Pittsburgh. And they can boast of a 30-10 pasting of the Patriots in San Diego.

Yes, the Broncos collapsed down the stretch. But it was the Chargers who pounded the final nail in Denver’s coffin.

“We got lucky,” Smith said. “But, if you play good, hard, physical football, it’s amazing how lucky you can get.”

jdonalds@projo.com