Despite the availability of players like Ndamukong Suh and DeMarco Murray, it was Washington that had the most successful move of the off-season in offensive line coach Bill Callahan.

Nothing excites NFL fans quite like their teams making big splashes in free agency. But through two games of the 2015 season, some of the players that got the biggest contracts haven’t changed the fortunes of their new teams. Ndamukong Suh, Byron Maxwell and DeMarco Murray have all had less than impressive debuts. The influence of others, like Jeremy Maclin and Rodney Hudson, has been less clear.

However, there is no disputing the early impact of one particular free agent. But it’s not a player. The best signing of the off-season was former Cowboys offensive line coach Bill Callahan landing with Washington. When you can make yourself better and weaken a division rival at the same time, that’s a coup.

Status quo for troublesome yet talented Ndamukong Suh

There’s no question that Washington is better up front. Just ask Rams coach Jeff Fisher, whose team and vaunted defensive line was dominated in a 24–10 loss on Sunday.

“They’re outstanding on coaching,” Fisher said. “Coach Callahan has done a great job with that offensive line. It’s Dallas all over again.”

• VRENTAS: 0–2 Eagles grappling for answers | KING: My top 15 teams

In two games against the Dolphins and Rams, whose defensive lines that are expected to be near the top of the NFL, Washington has averaged 171.5 rushing yards and allowed just three sacks.

While it’s certainly difficult to quantify line play and improvement, especially considering personnel changes and a quarterback switch from Robert Griffin III to Kirk Cousins, the early comparisons to last year are at least eye-opening.

Sour Rankings: Mariota's yard sale, Breaux's coverage worst of Week 2

Washington’s average rushing yards have increased per game (105.7 to 171.5) and per carry (4.22 to 4.64). Time of possession has increased over seven minutes per game. The total pressure generated on the quarterback has decreased from 35.7% to 31.1%—and that’s after facing two top pass rushing teams.

In Dallas, there has been a noticeable change with Callahan’s departure and the promotion of understudy Frank Pollack. While Dallas quarterbacks have faced less pressure to this point (yes, even with Tony Romo’s injury), the running game has fallen off a cliff, from 147.1 yards per game (4.63 per attempt) to 94.5 and 3.38.

Some will look at the decision not to re-sign running back DeMarco Murray as most of the problem (Joseph Randle, Darren McFadden and Lance Dunbar are trying to pick up the slack), but that would be fantasy-football driven. It’s not like Murray was the type of shifty runner who made players miss. He’s a power back who hits the hole opened for him and then makes his plays on the second level. Just look at the start of his Eagles tenure. The holes aren’t there, and he’s not making people miss with 21 carries for 11 yards through two weeks.

The Cowboys are playing with the same talented line: LT Tyron Smith, LG Ronald Leary (who was injured for Eagles game), C Travis Frederick, RG Zack Martin and RT Doug Free. If Murray didn’t make all the difference, then Callahan not being there has to be a factor.

Week 2 Snaps: Romo injury, stagnant Eagles throw NFC East into chaos

Washington entered the season with two new faces on the right side of the line. First-round pick Brandon Scherff replaced Chris Chester at right guard, and second-year player Morgan Moses is at right tackle for Tyler Polumbus. That’s a lot of inexperience to suddenly get up to speed, but watch them on film now, and you'll see precision, toughness and confidence. That’s Callahan’s imprint. I remember seeing it in the eyes of the Cowboys’ linemen when I went to Valley Ranch about a year ago to do a story on their talented unit.

• KAPLAN: Don't call Washington's ground success a surprise

“Ultimate technician, he’s focused on every single detail,” Frederick told me then about what Callahan was like in the offensive line room. “He’ll watch every play several times to specifically target every point. ‘Your hand is two inches to the right.’ Or, ‘Your foot came down too early or didn’t step in the right direction.’ He’s all over every point. He demands the best. Certainly helped me.”

Despite new management, Bears' once-proud defense still a disaster

If there was one play that exemplifies a unit working in harmony, it was Matt Jones’s 39-yard touchdown with 7:14 left in the first quarter against the Rams. It’s rare to ever go untouched on the way to the end zone, especially from 39 yards. If it happens, it’s usually a short-yardage play where everyone is near the line and one crease means it’s going the distance. This was a second-and-12 play. In this instance, only perfect blocking means an untouched score. It was a thing of beauty.

On a handoff over left tackle, left guard Shawn Lauvao pulled (leaving stud St. Louis defensive tackle Aaron Donald unblocked and free to race up the field) and kicked out strong safety T.J. McDonald. Left tackle Trent Williams blocked down on the end. Right after snapping the ball, center Kory Lichtensteiger sprinted upfield to the left and crossed with tight end Jordan Reed, who blocked one linebacker. Instead of just angling linebacker James Laurinaitis toward the sideline, Lichtensteiger scooped him and pinned him to the inside. That was the key block, which also shielded the free safety. Jones rode the hip of Lichtensteiger and went down the sideline, and no one laid a hand on him.

After another home loss, has window closed on Brees and the Saints?

That’s exquisite blocking. That’s Callahan.

The Cowboys probably didn’t have a choice in letting him walk. Callahan was the play-caller in 2013, but when Dallas gave those duties to new offensive coordinator Scott Linehan last season, Callahan likely agreed to stay on board for one more year if he was allowed to leave after it.

“A lot of people who have been mad, but you never see that with him,” Cowboys president Stephen Jones said last year. “Just the ultimate pro. He’s a big reason why we’re solid up there.”

For Callahan to ultimately wind up with an NFC East rival, the Cowboys had to have some sort of understanding with him.

Whatever the circumstances, Washington has to be thrilled with his arrival at 1–1 and with the arrow pointing upBill Cla thanks in good measure to the offensive line. That’s getting bang for your buck in free agency.