The Falcons had a four-pronged plan to improve their pass rush this season. Bryan Cox was the initial piece.

The other parts of the plan would come later. First, the Falcons hired Cox as defensive line coach in January and charged him with bringing all of the elements together.

But with the regular season half over, the Falcons’ pass rush still is weak. They’ve at least been better at stopping the run and pressuring quarterbacks lately, after they could do neither early in the season, but it’s not enough.

They need sacks.

“You see us moving the quarterback the last four games, but we haven’t sacked the quarterback,” Cox said. “That has not been up to our standards. But this group is doing everything that I am asking. They are working hard. You see improvement, but at the end of the day, we are 2-6. That’s the only stat that matters.”

There is a long list of reasons why the Falcons are flailing and, somewhat surprisingly, many of the bullet points include the offense. But the inability to get sacks is making it difficult for the defense to be anything more than occasionally adequate.

That’s why coach Mike Smith, like Cox, mitigates any praise for an improved pass rush by noting the Falcons have fewer sacks than any other NFL team.

““I do feel we have shown some improvement,” Smith said. “It’s not the improvement that we need.”

There has been no measurable improvement in the Falcons’ pass rush from last season, when it ranked among the worst in the NFL.

The Falcons rank last among 32 NFL teams with seven sacks. They stand 31th in sacks per pass attempt, after finishing 25th last season.

Football Outsiders compiles an adjusted sack rate that accounts for down, distance and opponent. The Falcons rank last in the metric this season, same as last season.

Pro Football Focus’ pass-rush rating accounts for hurries, hits and sacks. The Falcons rank 30th, after finishing 32nd in 2013.

Cox said the problem for his charges has been finishing once they get to the quarterback. He noted missed sacks by Kroy Biermann, Jonathan Babineaux, and Jonathan Massaquoi.

Cox said because players are getting to the quarterback, it shows the Falcons have the ability to get sacks.

“We have some guys that can do that,” he said. “But everybody wants more pass rushers. That’s the words that get everybody excited. But at the end of the day we’ve got to finish better.”

The lack of sacks has put stress on the Falcons’ secondary. Chicago’s Jay Cutler and Detroit’s Matthew Stafford both escaped pressure to complete long pass plays at critical points in games that the Falcons lost.

Given time, receivers are bound get open, and competent NFL quarterbacks standing in a clean pocket are likely to find them and deliver accurate passes. Falcons defensive coordinator Mike Nolan likens it to a “pass skeleton” drill in practice in which quarterbacks, running backs and wide receivers run pass plays with no linemen.

“You don’t want a pass ‘skelly’ game because that’s when the quarterback gets no pressure and he’s just throwing balls,” Nolan said. “When it’s a pass ‘skelly’ and the quarterback never gets sacked, there’s a lot of completions. If you don’t pressure the quarterback, that’s exactly what happens.”

It’s happened too often to the Falcons this season. So far their four-point plan hasn’t paid dividends.

The Falcons added massive defensive linemen Paul Soliai and Tyson Jackson in free agency. The idea was those two would shore the run defense, leading to better down-and-distances for the pass rushers.

The Falcons have stiffened against the run — their No. 12 ranking in yards per rush allowed is better than in any other defensive category — yet the sacks still haven’t come.

“We’ve just got to focus on stopping the run,”defensive end Osi Umenyiora said. “As long as we do that, we will have chances (for sacks).”

The Falcons switched Umenyiora, their most accomplished pass rusher, to a part-time role on passing downs. Umenyiora slimmed down in an attempt to add quickness in anticipation of the new task. He has just one sack in 149 pass-rush attempts, according to Pro Football Focus.

The Falcons have increased the playing time for their young pass rushers. They planned on someone emerging from the group of Malliciah Goodman, and Stansly Maponga and Massaquoi.

Maponga has played only 65 snaps. Cox said Goodman hasn’t played up to his potential after a strong camp. Massaquoi, the team leader with two sacks, has shown promise.

Before joining the Falcons, Cox had coached Tampa Bay’s front seven and served as a pass-rushing specialist coach in 2012 and 2013. He served in a similar role with the Jets, Browns and Dolphins over six seasons.

“At the end of the day, when I took the job, we knew we had some things we had to fix in terms of run and pass,” Cox said. “If you had to fix one, you want to fix the run part of it first. We’ve done a good job of it so far.”

Now the Falcons just need some sacks.