OWINGS MILLS, Md. -- A day after a deflating 23-20 loss to the Buffalo Bills, Baltimore Ravens coach John Harbaugh was asked whether he was worried how two second-half collapses could affect his team’s mindset going forward.

“Well, we have a team psychologist, Dr. Trish, and she does a great job,” Harbaugh said Monday. “So, I'll let her worry about that, and we'll worry about the football because we have some strong-minded guys -- and our guys are gonna be thinking about getting the next stop.”

From 2008 until this season, the Ravens had been the NFL’s best closers, winning 61 straight games under Harbaugh in which they had led by 17 points or more. That was tied for the fourth-longest streak by a head coach to begin their career in the Super Bowl era, according to research by the Elias Sports Bureau. The Steelers had won 58 straight from 2008 until this season, and Mike Tomlin’s streak remains active at 64.

Now, all of a sudden, the Ravens rank as the league’s worst finishers, failing to hold a 21-point lead against the Miami Dolphins in Week 2 and a 17-point advantage against the Bills on Sunday. Baltimore has been outscored 43-9 in the fourth quarter.

Quarterback Lamar Jackson and the offense have sputtered to sustain drives after halftime, and the defense has struggled to get teams off the field.

“It’s only Week 4,” Jackson said. "I’m not looking at this like we have had a disappointing season. Guys are just coming back healthy now, and I feel like we are going to hit our peak at the right time.”

Here are three reasons why the Ravens haven’t been able to close out games like they’ve done in the past:

Lack of a run game: Baltimore built a reputation of imposing its will late in games with a mauling offensive line and hard-nosed running backs. The Ravens would churn out drives of double-digit plays that would eat up chunks of clock. Teams couldn’t rally back from deficits against Baltimore because they simply didn’t have the ball.

From 2008 to 2021, Baltimore running backs led the NFL with 6,378 yards in the fourth quarter. This year, the Ravens haven’t had the same production on the ground in the second half and haven’t shown the same faith. Baltimore’s running backs of J.K. Dobbins, Justice Hill, Mike Davis and Kenyan Drake managed 45 yards in the fourth quarter. As a result, the Ravens have handed the ball to them 13 times in the final quarter, the fifth-fewest in the league.

"We can’t come out in the second half and not move the ball five yards,” Ravens offensive tackle Morgan Moses said. "When you come out in the second half and you get the ball first, you’ve got to make movement, you’ve got to make that defense feel you, and we didn’t do that.”

Harbaugh provided some optimism, announcing that running back Gus Edwards (knee) will begin practicing this week. Edwards, who is on the physically unable to perform list, has gained 708 yards in the fourth quarter, which was the fourth-most in the NFL from 2018 to 2020.

Less efficient QB play: Jackson has played better than during his 2019 NFL MVP season in most areas this year, except for late in games. On Sunday, he missed a wide-open Devin Duvernay in the right corner of the end zone on fourth down and threw an interception with 4:09 left in the game.

Jackson’s QBR in the fourth quarter (24.3) ranks 28th in the league, putting him behind the likes of Mitchell Trubisky, Baker Mayfield and Mac Jones.

“I feel like we just have to execute,” Jackson said about the problems offensively in the second half. "I felt like we had some chances to keep drives alive on the field, but we just have to execute. We just have to do a better job and that way we will have success.”

In his first four seasons, Jackson completed 63.3% of his throws in the fourth quarter, recording 20 touchdowns and six interceptions. This season, Jackson has connected on 59.4% of his passes in the fourth quarter, producing no touchdown passes and three interceptions.

Getting teams off the field: For years, the Ravens relied on big-name players making clutch plays, whether it was Ray Lewis with a hit over the middle, Ed Reed with an interception or Terrell Suggs with a strip-sack. This season, Baltimore’s fourth-quarter mishaps have included missed tackles, blown assignments and dropped interceptions.

On third downs in the fourth quarter this year, opposing quarterbacks have completed 9-of-12 passes (75%) for 186 yards (which are 73 more than any other team). They have thrown four touchdowns and one interception while getting sacked once.

From 2008 to 2021, the Ravens had twice as many sacks (54) as touchdown passes allowed (27) on third downs in the fourth quarter.

"When we get the plays that we had out there to capitalize on, we’ve got to capitalize on them. It’s as simple as that,” Ravens inside linebacker Patrick Queen said. "They [the offense] didn’t get the fourth down; we’ve got to go out there on defense and stop them — that’s our job. When it’s the end of the game, we’ve got to dig deeper.”