How was Justin Herbert able to make the cross-body throw on the run that resulted in Derius Davis’ go-ahead touchdown?

How was Joshua Palmer able to get his right hand on a deflected pass, turn around and corral the tipped ball along the back edge of the end zone for a crucial two-point conversion?

How were the Chargers able to recover from an atrocious opening half to secure a season-defining 34-27 victory over the Denver Broncos at SoFi Stadium on Thursday night?

“Our guys,” coach Jim Harbaugh said, “really just stayed the course.”

The Chargers are 9-6, and short of a one-in-a-billion disaster, they will reach the playoffs.

With their remaining games against the New England Patriots (3-11) and Las Vegas Raiders (2-12), they could very well finish the regular season with 11 wins. Already, they have overtaken the Broncos for the No. 6 seed in the AFC. They officially can clinch a postseason berth this weekend if the Indianapolis Colts and Miami Dolphins both lose.

Chargers coach Jim Harbaugh hugs Hassan Haskins (28), whom he coached at Michigan, after the running back’s touchdown against the Broncos.

(Gina Ferazzi / Los Angeles Times)

The Chargers have an offense with limited weapons and a defense that can’t stop the run, but they have outperformed even the most optimistic of preseason forecasts, which reveals the degree to which Harbaugh has infused his spirit in them in his first season as coach.

They lost three times in a four-game span early in the season and responded with a four-game winning streak.

They received a brutal reality check from the Baltimore Ravens in Week 12 and bounced back with a victory on the road over the Atlanta Falcons.

They entered their most recent meeting with the Broncos on another 1-3 stretch and answered by equaling their highest scoring output of the season.

“We talked about it all week, how important these games are, especially in December and January,” Herbert said. “We knew the implications of it, and we emphasized all week, ‘Hey, this is a playoff game to us.’”

Harbaugh said he knew his players would show up.

“Our guys never wavered,” Harbaugh said.

The players echoed his thoughts when explaining their comeback against the Broncos. The Chargers were down by eight points at halftime and by 11 in the third quarter, but asked what changed in the second half, they pointed to what didn’t change.

“I think we stuck with it,” running back Gus Edwards said.

Edwards rushed for only 18 yards in the first half, but the Chargers didn’t abandon the run. Edwards picked up a combined 50 yards in the third and fourth quarters.

“We’re equipped with that skill of being able to respond,” Palmer said.

Chargers running back Gus Edwards (4) runs five yards for a third-quarter touchdown against the Broncos.

(Gina Ferazzi / Los Angeles Times)

The players believe in Harbaugh, and why wouldn’t they?

Harbaugh and his staff might not be able to make up for all of the roster’s deficiencies, but they have maximized what the team has. Consider how Harbaugh took advantage of the obscure fair-catch free-kick rule to help his team pick up three points with time expiring in the second quarter.

Was Palmer aware of that rule?

“I was not,” Palmer said with a chuckle, “but now I am.”

The atmosphere in the locker room was festive.

“Just a special win, special group of guys,” Harbaugh said.

Harbaugh joked how the Amazon Prime broadcast team was likely uncertain of which players it should invite on its postgame show.

“That would have been a tough one,” Harbaugh said. “Ten guys you could have picked from.”

He started naming them, starting with Herbert and safety Derwin James Jr. He mentioned Kendall Williamson and Dicaprio Bootle, who were elevated from the practice squad.

When Harbaugh was asked about Davis’ touchdown reception, he shouted, “D.D.! They could have had him at the podium!”

These Chargers don’t sound like Brandon Staley’s Chargers or Anthony Lynn’s Chargers. They don’t play like Staley’s Chargers or Lynn’s Chargers.

That in itself will make this a productive first season for Harbaugh, regardless of how it ends. He has changed the culture of a franchise that desperately required a change in culture, establishing a foundation on which its future teams will be built.