SANTA CLARA, Calif. -- After doing little to address what many believed was their biggest need during the offseason, the San Francisco 49ers suddenly found themselves with a chance to land the ultimate solution to their edge-rushing woes last week when the Oakland Raiders fielded offers for defensive end Khalil Mack.

Landing Mack would have given the Niners the exact piece they've been missing. And general manager John Lynch was well aware of it. Which is why he engaged in the bidding for the three-time Pro Bowler.

DeForest Buckner is the 49ers' best rusher, but his presence is often limited by being lined up on the interior. Robin Alam/Icon Sportswire

"We would have been foolish not to (get involved)," Lynch said. "The guy is a spectacular player. We've always said we're going to exhaust every option to improve our team. So, we did. We went in aggressively."

Ultimately, Mack's price was more than the 49ers wanted to pay and Oakland traded him to the Chicago Bears.

Landing Mack was a longshot, but it still leavers the Niners with a nagging issue: How can they jump-start a pass rush that has lagged near the bottom of the league since 2012?

It's not that the Niners haven't tried. They've spent three of their past four top picks on defensive linemen: Arik Armstead, DeForest Buckner and Solomon Thomas are all considered better rushers from the interior.

Interior pressure can only do so much without a strong finisher off the edge. Lynch, his staff and coach Kyle Shanahan have spent the past couple of offseasons looking closely at potential free-agent outside rushers such as Melvin Ingram, Jason Pierre-Paul, Chandler Jones and Ezekiel Ansah. None hit the open market because of the franchise tag.

The draft hasn't offered much more in the way of help. In 2017, Myles Garrett was clearly the best at the position but he went No. 1 to Cleveland. This year's crop of outside rushers was lacking again, save for Bradley Chubb, who went to the Denver Broncos four picks before San Francisco.

All of which left Lynch and the Niners seeking alternative ways to bolster the pass rush, including taking a flier on underachieving Jeremiah Attaochu, hiring a pass-rush specialist in Chris Kiffin and adjusting the scheme to remove what coordinator Robert Saleh has referred to as "gray areas."

“We wanted to throw a number of options at people in terms of our pass rush," Lynch said. "We’ve had an emphasis on maximizing whatever we have on pass rush, via personnel, via coaching additions, via scheme. All those things."

Last year, the 49ers tied for 26th in the NFL in sacks with 30. They were also tied for 26th in sacks per drop back. While sacks aren't everything in terms of creating an uncomfortable pocket, the Niners were only a little better in pressure percentage, creating duress on the quarterback on 27.6 percent of drop backs, which ranked 21st in the league.

The 49ers haven't had a player with more than 6.5 sacks since Aldon Smith had 19.5 in 2012. Veteran Elvis Dumervil led the Niners last year with 6.5 and the team decided not to pick up his option for 2018. He retired in the preseason. Dumervil's departure leaves Buckner and Thomas as the team's returning leaders in sacks with three each.

After releasing Attaochu, the Niners' biggest outside addition could actually be Kiffin. The son of legendary defensive coordinator Monte Kiffin, Chris Kiffin was hired to the newly created job of pass-rush specialist.

That job includes figuring out where each lineman is best used and developing games and stunts to create favorable matchups. When Saleh went back and watched tape of last year's defense, he saw a group that was sound in the run game, in coverage and in alignments with a defined role for every player. The same wasn't true for the pass rush.

Saleh charged Kiffin and defensive line coach Jeff Zgonina with making pass rush responsibilities for each player a cut and dry proposition.

“(It's) creating a black and white picture so those guys understand exactly what job each person has, so they can learn how to play off of each other and they can rush as a unit," Saleh said.

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To make that happen, Kiffin has tapped into the expertise he learned as a ball boy for his dad and Rod Marinelli with the dominant Tampa Bay Bucs defense of the late '90s and early 2000s. Kiffin spent that time watching the likes of Simeon Rice and Warren Sapp work off each other on their way to becoming one of the most dominant defenses of the past couple of decades.

Kiffin emphasizes things like footwork and understanding the strengths and weaknesses of the player next to you, likening it to a the way a basketball team works.

Take Buckner as an example. As the three-technique defensive tackle, Buckner's specialty is getting push up the field using his unique combination of strength and quickness. In the preseason, Buckner often found himself rushing next to veteran end Dekoda Watson. After studying their reps together, Buckner and Watson made a habit of noting how the other likes to attack, so if Buckner pushes quickly on the outside edge of the guard, Watson can come in underneath, allowing Buckner to occupy the guard and the tackle.

"You have got to know all your brothers on the D-line, what type of rusher they are," Buckner said.

The other challenge for Kiffin & Co. is finding ways to create one-on-one matchups, especially for Buckner, who Saleh calls the team's best player. In training camp, the 49ers toyed with lining Buckner up on the outside, similar to what Jacksonville does with Calais Campbell. While that's something the Niners could explore further, they also don't want to take him away from his best spot.

“You are going to put the guys where you think they’re the best," Shanahan said. "If you think someone’s great on the inside and they’re OK on the outside, you don’t want to make them OK.”

It might be overstating things to say pass rush will make or break the Niners in 2018, but there's little doubt it will play a big part in how far they go. Part of the reason for their lack of quarterback pressure in recent years is the fact that they've found themselves trailing in so many games. Last season, they had just seven sacks in the fourth quarter or overtime, tied for 25th in the league.

But if you're looking for an indicator that things could be better because the Niners should be closer in more games, look no further than how they fared in their five wins to close last season with quarterback Jimmy Garoppolo. The 49ers made contact with the quarterback on 17.8 percent of snaps in the fourth quarter and overtime in those final five games, the best rate in the NFL.

That type of pressure is often a good indicator that sacks will come. And despite all of those steps the Niners are taking to make life more difficult for quarterbacks, it still comes down to something simple.

"When you get a one-on-one, you’ve got to win," Saleh said. "That’s what football is. You’ve got scheme, you’ve got all the rules, fundamentals. You’ve got everything... the structure of it looks good, the rules look good, the communication is coming along, and now when you’ve found yourself in a one-on-one, expect to be in a one-on-one and the expectation is that you win. Turning all of this into production is the next step.”