The turnaround the Redskins displayed last season, going from last in the division in 2014 to an NFC East title in 2015, can be directly correlated with the performance of Washington's offensive line.
The ascension of the Redskins' blockers is linked to an emphasis Washington made to fix that area last offseason. Two moves in particular that the Redskins made -- hiring offensive line coach Bill Callahan and drafting right guard Brandon Scherff -- really set the tone for Washington's offensive front in 2015.
In just one season, Callahan, who has been a successful head coach and offensive line coach at the college and professional levels, turned the Redskins from one of the worst pass-blocking teams in the NFL to one of the best.
With three different quarterbacks in and out of the lineup, plus injuries up and down the offensive line, the Redskins allowed the second-most sacks in the league (58) in 2014.
Last season, with quarterback Kirk Cousins as the full-time starter, the Redskins' blockers kept their signal-caller much cleaner and allowed just 27 sacks, which put them only behind the Ravens (24), Jets (22) and Rams (18).
However, Callahan and the Redskins would like to see some improvement in the team's run blocking moving forward. Washington had one of its most lackluster seasons in recent memory in terms of rushing, but head coach Jay Gruden defended his blockers throughout the season, saying the running lanes were open, but the Redskins' running backs failed to find them at times.
Fixing the running game is high on Callahan's to-do list, but so is continuing to develop Scherff, Washington's first-round pick last year (fifth overall).
Callahan did an excellent job of grooming Scherff in each of their first seasons in Washington. Scherff was named to the Pro Football Writers of America's all-rookie team after playing in all 16 regular-season games and the Redskins' playoff loss to the Green Bay Packers.
Scherff was as reliable as it gets for the Redskins as a rookie. In fact, Scherff played all but one snap for Washington in 2015 and made a seamless transition from tackle to guard during the preseason.
The Redskins' offensive line also got major contributions last season from All-Pro left tackle Trent Williams and second-year right tackle Morgan Moses. Both tackles are products of solid drafting by Washington and appear to have the edges locked down for the foreseeable future.
But there were some injury concerns in the middle of the offensive front last season. Left guard Shawn Lauvao was shut down early during the season and placed on injured reserve with an ankle injury in September, but Spencer Long ended up taking over and filling in admirably in Lauvao's absence.
Redskins center Kory Lichtensteiger was having an excellent season before his year was also cut short by an injury. Washington placed Lichtensteiger on injured reserve in early November, and Josh LeRibeus, who is naturally a guard, took over as the starting center for the remainder of the season.