49ers aim to present more sophisticated defense next season

SANTA CLARA - The 49ers believe they can improve their historically bad defensive backfield without changing it.

They brought back all five starters from a 2018 secondary that intercepted only two passes (a new NFL low), broke up just 39 passes (a league low in 2018) and gave up a quarterback rating of 105.4 (second-worst in the NFL). And yet, the 49ers insist those ?numbers will improve next season, because the 49ers will disguise their coverages and use quality edge rushers they didn’t have in 2017 or 2018.

“(Playing defense without good edge rushers) is like telling an offense to get by without a good quarterback,” defensive coordinator Robert Saleh said Wednesday after OTAs. “It starts with the (defensive) front. It’s a big man’s game. And our front has a chance to be special. It’s a very talented group. That will finally come to light because we’ve got the speed element (with Dee Ford), along with Nick Bosa’s power to fill out the edges.”

Last season, the 49ers’ primary edge rushers were Cassius Marsh and Ronald Blair, and they recorded only 5.5 sacks apiece. Neither scared opposing offenses or forced opposing quarterbacks to throw the ball quickly.

“When an offense changes the way they approach us and attack us, then I know we’re getting pressure on the quarterback and changing their entire philosophy,” Saleh explained. “Last season, the routes we were seeing were long-developing. The quarterback was able to go through his progressions and either throw it away or take a checkdown. Now, he can’t go to his next progression because if he does, he should be getting hit by somebody. That didn’t happen as frequently as we would’ve liked a year ago.”

Saleh believes the 49ers’ new and improved pass rush will force quarterbacks to rush in the pocket and throw the ball quicker than they’d like to, which will allow the 49ers’ defensive backs to play faster, better and more aggressively than they did the past two seasons.

“You guys remember the Oakland game?” Saleh asked reporters in the 49ers’ auditorium. He was reminding reporters the 49ers beat the Raiders 34-3 last season and sacked quarterback Derek Carr seven times. That was the 49ers’ best defensive performance of 2018.

“The D-line was just wreaking havoc,” Saleh said. “If you really go back and dissect that tape, the back end (of the defense) just got faster and faster and faster as the game went on because it is tied to the (pass) rush.”

Meaning the 49ers’ defensive backs could jump routes early in the play. They knew they wouldn’t have to cover for four or five seconds, because the pass rush forced Carr to throw the ball quickly. The 49ers intend to bother quarterbacks more often next season.

The 49ers also intend to confuse opposing quarterbacks.

The past two seasons, the 49ers defense didn’t try to confuse anyone. The other team could figure out before the snap exactly what coverage the 49ers were using based on the location of the free safety.

Now, new defensive backs coach and passing game coordinator Joe Woods will add deception to the defense, simply by concealing the identity of the free safety before the play starts.

“We’re moving into that area where the free safety and strong safety are interchangeable,” free safety Adrian Colbert said in the 49ers’ media room. “In the past, the strong safety would always be in the box (near the line of scrimmage), and the free safety would be in the post (the deep middle of the field).

“You would know who the free safety was. If you saw him in the middle of the field, you knew we were running Cover 3. Now, you don’t really know, because the free safety could be in the box and we’re showing different looks and moving around a lot more than we used to. We have way more (disguises) than we had the past two years.”

To fit the new defensive scheme, Colbert has added 15 pounds of muscle so he can play strong safety some of the time. And strong safety Jaquiski Tartt has taken reps in the deep middle of the field during OTAs so he can play free safety as needed next season.

Tartt likes the changes the 49ers have made on defense.

“We should have done this last year,” he said.