KANSAS CITY, Mo. — Last year, the Kansas City Chiefs started the season with a nine-game winning streak and all the attention was on the defense coordinated by Bob Sutton. His group was productive and the foundation for the club’s quick start that pushed them to the playoffs. However, during the second half of the 2013 season, the defense faltered against the run and pass.

This season as the Chiefs come back from their bye week and prepare to play divisional rival San Diego, the KC defense has not been as productive as last year’s unit and deserves its share of the blame for the 2-3 record at the bye week. Still, the defense has been the most consistent part of the Chiefs’ on-field efforts through five games. The offense has been all over the place. The special teams have not been consistent producers and have made a number of key mistakes.

But the defense has been consistent even though it wasn’t forced to play without key starters at all three levels, including the unit’s emotional and tackling leader, inside linebacker Derrick Johnson. Sutton’s side of the ball has performed from average to good all season:

— The defense has allowed an average of less than two touchdowns per game, with a total of nine scores this season.

— The Chiefs are one of six teams not to have allowed an opposing quarterback a 300-yard passing game. The others are Green Bay, Miami, Minnesota, New England and San Francisco. The most productive passer was Tennessee’s Jake Locker, throwing for 266 yards.

— One reason that opposing passers have not torched the ’14 defense is due to the Chiefs limiting big pass plays. They’ve given up 11 completions of 20 yards or more, compared with 13 allowed last season after five games. The real difference comes here: Last year, they allowed passes of 69, 53 and 49 yards, all for touchdowns. This year, the longest completion they’ve given up is 48 yards.

— Last year after five games, the Chiefs had allowed five running plays for more than 25 yards. This year, the longest run they’ve allowed is 24 yards.

— They have not allowed a rushing touchdown. The only other NFL defense that can match that is Buffalo.

The most visible improvement has been far fewer receivers running wide open down the middle of the field. The lack of those big plays has given a shot of confidence to the entire defense, and especially a secondary where for most of the season there have been three new starters compared with last year.

“A lot of it comes back to technique and I think (assistant coaches) Emmitt Thomas and Al Harris have done a great job working technique,” Sutton said. “Whether it’s hand placement or footwork. If you get in trouble low, it’s hard to make up on some of these guys because sometimes it’s just a matter of pure speed. If you add speed with accuracy, the deep ball is still the hardest ball to throw. There can be some long foul balls out there that are open, but they’re not in the park.

“I think the players have gotten better at it. I think some of disguises have been good and that’s helped us. I think overall it’s like most of these things; it’s not one exact thing. But I think it’s the players just understanding the importance of being on top of a receiver is really critical.”

There have also been some changes made by Sutton and the defensive staff. While the defensive coordinator would not provide a direct answer, it has been more apparent that the Chiefs are playing more zone defense this year than they did in the 2013 season. They are not nearly 100 percent press coverage on the outside receivers like they were last season.

“We really haven’t changed schematically a lot,” Sutton said. “I don’t know honestly. I can’t tell you what the statistics are, but I would say it is pretty close (to last season’s ratio of man coverage to zone.”)

What has not happened are takeaways; last year after five games, the Chiefs had 15 interceptions/recovered fumbles. This year, it’s just three takeaways (2 interceptions, 1 recovered fumble) and all came in a victory over New England. They were shut out in the other four games. That does not fit the personality of the defense

Ahead for the Kansas City defense are nine opponents for 11 games and only two teams currently ranked in the league’s top 10 for offensive yards: Pittsburgh (6) and Denver (9). The Chiefs have two games with San Diego (12) and Oakland (31), plus games against St. Louis (13), Seattle (20), Buffalo (25), Arizona (28) and the New York Jets (30).

NOTES: WR Donnie Avery (sports hernia) was declared out of Sunday’s game against San Diego. . . S Eric Berry returned to practice on Wednesday for the first time since Sept. 14. . . CB Chris Owens (knee contusion) did not practice Wednesday.