The best of lines, the worst of lines

SAN FRANCISCO — The 49ers have given up a league-worst 19 quarterback sacks through four games.

Blame the offensive line.

The 49ers are tied for second in the NFL with 20 offensive plays of more than 20 yards.

Credit the offensive line.

There has been plenty of good and bad with the 49ers’ offense. The offensive line deserves blame and credit for the team’s production in the first season of coordinator Mike Martz’s high-risk, high-reward offense.

Although most of the focus has been on the frequency with which 49ers quarterback J.T. O’Sullivan has gotten sacked this season, New England Patriots coach Bill Belichick sees the other side, too.

“The bottom line is that the 49ers are throwing the ball down the field and they’re making big plays in the passing game,” Belichick said. “They’ve gotten hit a couple of times, but they’ve also hit the defense plenty, too. It’s a give-and-take thing.”

Belichick has had two weeks to prepare for the 49ers’ offense, as the Patriots are coming off their bye week. The teams meet today at Candlestick Park in a game that will feature two of the top football strategists — Belichick and Martz — going head to head.

“There is no telling with two weeks to prepare for us what they might do,” 49ers coach Mike Nolan said. “Their base stuff will be the same, but there probably will be some wrinkles in there. I would expect that. Otherwise, it would be out of character for what they do.

“Obviously, he has gone against Mike on a number of occasions, so there will be some carryover there. Both he and Mike, when they go against each other, will try to figure out some little wrinkles to show one another.”

Belichick, obviously, will be looking for ways to get more pressure on O’Sullivan, who was sacked six times last week in the 49ers’ 31-17 loss to the New Orleans Saints. The Patriots have recorded six sacks in their three games this season.

The challenge for Martz is to keep O’Sullivan’s uniform clean, while also picking the right times to try to get the ball down the field.

O’Sullivan has completed 16 passes of more than 20 yards this season. That means the pass protection has held up at times — and not at others. The 49ers surrendered a franchise-worst 55 sacks last year. At 4.75 sacks per game, the 49ers are on pace for 76 this season.

“Sometimes in this offense, the quarterback has to hold it to go downfield and get those big chunks like you’ve been seeing,” 49ers left tackle Joe Staley said. “So every time we get a 20-yard play, it’s because of good protection and he’s been able to stay in the pocket. It takes a lot of time for those plays to develop.

“We have to do a better job of finishing those seven-step drops and giving him all the time he needs. It falls on us.”

Staley has given up a team-high five sacks for minus-25 yards, according to STATS LLC. Right tackle Barry Sims has surrendered four sacks for negative-21 yards.

“Our jobs are to block them until the ball is gone,” Sims said. “Sometimes the ball comes out quickly, and sometimes it does not. But that doesn’t really change our responsibilities. We have to block their guys and keep them off our quarterback. Sometimes it’s harder than others.”

Of course, not all the blame falls on the offensive line. O’Sullivan has been responsible for several sacks with his inability to throw the ball away to avoid taking a loss of yardage.

But he has also shown the willingness to endure a hit if it gives his receivers an opportunity to run their routes down the field.

“We want to have those big chunks, but we don’t want to have any pressures or sacks or hits on the quarterback,” Staley said, “because 19 sacks is unacceptable.

“It comes down to finishing. If you look at the film, we do a good job at initial contact. But where we’re having our breakdowns is guys are getting a second and third chance in long protections. We have to do a better job against the Patriots.”

For more on the 49ers, go to Instant 49ers at 49ers.pressdemocrat.com. You can reach Staff Writer Matt Maiocco at 521-5492 or matt.maiocco@pressdemocrat.com.