When Browns players and coaches have been asked to outline the recipe for their offensive success over the last month, their responses could form a list that runs far beyond only a few bullet points.

The play-calling has been opportunistic. The top playmakers have dazzled when the football is in their hands. The cohesion of the group at a whole has grown more evident every week.

But one of the most commonly mentioned reasons for success is related to a crucial offseason acquisition made in late January: the hiring of Bill Callahan.

Callahan, the Browns' offensive line coach, has more than 40 years of coaching experience at college and professional levels and has left a footprint on nearly every team he's coached. His veteran presence was needed to jell Cleveland's revamped offensive line — which included the big-ticket signing of Jack Conklin, first-round selection of Jedrick Wills Jr. and impressive rise of Wyatt Teller — and mold the Browns into the wide-zone schemes and run-heavy styles from coach Kevin Stefanski.

Five weeks into the season, Callahan's presence certainly has been felt. The endless amount of praise has proven that.

From center JC Tretter: "It has been really, really nice to work with him. He is so experienced. He has seen everything. He is an asset for us to have."

From Teller: "He stayed on my butt. He has made sure that I know that I have a lot to work at and a lot to improve."

From running back Kareem Hunt: "Coach Callahan has been putting (the offensive line) in a great position to make their blocks. He really does a great job of emphasizing the things that need to get done.

From Stefanski: "He does a great job with those guys. They are taking to heart the coaching that Coach Callahan provides."

The proof is everywhere, including the numbers.

Cleveland's offensive line ranks first in the NFL with only 22 quarterback pressures allowed this season, and its seven sacks allowed are tied for fifth-fewest in the league. The Browns' 188.4 rushing yards per game are the most in the NFL and third-highest in franchise history, and the team's 1,973 total scrimmage yards are ninth in the NFL, third in the AFC and fifth-most by a Browns team through the first five weeks of the season.

Those numbers all trace back to the offensive line and showcase why the Browns have developed into one of the top offensive units in the NFL.

It also shows the effect Callahan has made on a unit that was tabbed one of the biggest areas in need of improvement for the Browns before 2020. Now, the offensive line is arguably Cleveland's biggest strength.

"Coach Callahan and (assistant offensive line) Coach (Scott) Peters do an exceptional job of getting those guys ready each week," offensive coordinater Alex Van Pelt said last week. "With all the drill work they do on the side, those guys are constantly working as soon as they step on the field from pre-practice to post-practice. I know that is paying off now."

Callahan could create a college-level textbook on the craft of being an offensive lineman by compiling his responses to questions about various players and positions over his years of coaching. He doesn't take any shortcuts when it comes to his game prep and examination of opposing players, and he always backs up his philosophies and technique suggestions with reasons that show the intricacies of what it means to be a master in the trenches.

Take his response to a Week 3 question about Wills, whom Callahan has worked closely with since the Browns selected him with the 10th overall pick of the 2020 draft, as an example of Callahan's coaching. Wills' transition to left tackle from right tackle, where he played at Alabama, was one of the main storylines of the season, but he's fit in like a puzzle piece on the left side of Cleveland's line and is on track to be another young player who thrived under Callahan's tutelage. 

"I don't think you ever settle into left tackle because your challenges are dramatic week in and week out," Callahan said. "You can have a speed-type rusher who is a little bit lighter and a lot of quickness, or you can have a power rusher that you are faced up against. Jed is going to have to adjust and adapt his strikes and his counters and find those windows of opportunity. 

"When I say windows, when a pass rusher is moving up the field and his arms are moving, there are fractional seconds where you can lay your punch and lay your hands and get your fit and get your handle so that you can control the rusher. That timing is different week in and week out. When that window opens, the ability to shoot your hands and get them inside to control the rusher becomes more important. Everybody has a different move and everybody has a different combination and a different window where you have to obviously time up your hands."

Callahan's clinics are a spectacle for his players during every practice, too. He rarely gives a compliment to a player without weaving in a constructive criticism about how their play could've been better, and his devotion to spending time with everyone in the offensive line group has forged a close chemistry among all players.

"I think everybody is just on the same page," Tretter said. "Everybody is doing the right thing. We all understand where we are supposed to be, where we are supposed to be going to and how we are supposed to go there."

Callahan's coaching has helped place the Browns near the top of the early race for the playoffs. They'll face perhaps their toughest challenge of the season this week against the Pittsburgh Steelers, who have the top defense in the NFL and a variety of playmakers capable of giving any offense a forgettable Sunday, but the Browns are confident they'll be up for the task.

Their offense has plenty of reasons to believe it can compete with the best. 

Having Callahan on their side is certainly near the top.