When Head Coach John Harbaugh first arrived in Baltimore in 2008 to start building the team, he and those around him said, "You start in the trenches."
Now, heading into the offseason, it looks like the Ravens have reached a point where they hardly have to worry about any tweaks.
The Ravens' strength in 2015 will be their offensive and defensive lines, thanks to nifty drafting and quality veteran additions.
"A team is built from the trenches out, and we were pretty strong in the trenches this year," Harbaugh said last Tuesday.
"That's the foundation of our team, and we want to keep improving that and keep building on that, and we want to be as great as we can be on both sides of the ball up front."
The Ravens had a very good offensive line this year, and all five starters are slated to return.
Left tackle Eugene Monroe struggled with injuries, but even he was adequately replaced by rookie free agent James Hurst. Left guard Kelechi Osemele was a mauler all year. Center Jeremy Zuttah helped dramatically sure up the middle.
Right guard Marshal Yanda was a Pro Bowler. Right tackle Rick Wagner was graded as the top pass-blocking right tackle in the NFL by Pro Football Focus (PFF). When he went down in Week 16, rookie fifth-round pick John Urschel stemmed the tide by sliding in at guard.
"The future is really great for our offensive line," Harbaugh said.
This year, the unit paved the way for the NFL's No. 8-ranked rushing offense (126.2 yards per game). They dramatically improved after Baltimore had a league-worst 3.1 yards per carry last season.
Baltimore's offensive line also gave up just 19 sacks, the second-fewest in the league. Quarterback Joe Flacco was protected better than he ever has been in his seven-year career.
Now the challenge is repeating that success.
"Once you start playing at a certain level and your coaches develop an expectation, you have to be able to maintain that and be consistent," Osemele said.
Monroe and Osemele don't think that will be a problem given how hard the offensive line works.
"I think if we maintain the same guys in the room, the sky's the limit," Monroe said. "You can watch the film. We've been the most physical line in the league and that's only going to get better."
The defensive line should be another area of strength considering an emergence of young talent.
The Ravens know what they have in Haloti Ngata, who was likely on his way to another Pro Bowl season before his four-game suspension. Ngata was making plays all over the field.
In his first year as a starter, defensive tackle Brandon Williams played every game and registered 47 tackles, a half-sack and two forced fumbles. He was flat-out dominant at times, pushing centers into the backfield and creating havoc in opposing run games.
Rookie defensive tackle Timmy Jernigan missed four games due to knee and ankle injuries, but was impactful when he was on the field.
He registered 23 tackles and four sacks, then added another sack on New England's Tom Brady in the postseason. Jernigan filled in well when stepping in for Ngata during his suspension.
"Successful season," Jernigan said. "Coming into the season, I knew it was going to be tough playing behind a future Hall of Famer. But coming in and getting five sacks, that means a lot to me. I feel like if I played a little more, maybe the numbers could have been higher."
One factor for the defensive line will be whether veteran Chris Canty retires, which he is debating. Canty started all 11 games he played in, recording 33 stops and a half-sack.
If he does leave, Baltimore would likely lean on last year's fourth-round pick, Brent Urban, who suffered a season-ending knee injury but was very impressive last summer.
