By Julie Buehler

Through 3 seasons in San Francisco, under head coach Jim Harbaugh, the 49ers have done things few teams in NFL history have done.

They set a new record for turnover margin.

Played in 3 straight NFC Championship games and Super Bowl 47.

They lost only 11 regular season games, averaging 12 wins a season. Meanwhile, their division rivals lost an average of 8 games a season.

The Niners are the only team in the division that has not suffered a losing season between 2011-2013.

They amassed long stretches of sustained success and most impressively, returned one of the NFL’s most historic franchises to relevance as a new billion-dollar stadium was built and will be hosting historic Super Bowl 50.

They’ve built that success with a consistent model of great defense, a pounding running attack and limiting turnovers. Basically the aspirations of every football team at every level.

In the past 3 seasons, the Niners have given up the NFL’s fewest turnovers, allowed the fewest points, fewest rushing yards, are behind only the Minnesota Vikings in most rushing yards and behind only the New England Patriots in highest winning percentage.

So what Jim Harbaugh did in his first 3 years worked. And it worked very well.

The Niners are 1-2 after week 3, just as they were last year, but this year, it’s different.

Last year, after the Niners lost consecutive games, I didn’t think there was much cause for concern, and the season proved that out, they were 1 play away from returning to the Super Bowl, and don’t forget, the team that beat the Niners in Super Bowl 47, the Baltimore Ravens, didn’t even make the playoffs.

But this year is different, for a lot of reasons. While the Niners have the same record they did at this time last year, there’s great cause for concern.

First: the defense that was the NFL’s best run defense and scoring defense over the span of Harbaugh’s tenure is a shadow of it’s former self.

Navarro Bowman, one of the NFL’s best linebackers, won’t return from a knee injury sustained in the NFC Championship until at least week 7, more likely week 9.

Aldon Smith, the guy with the 2nd most sacks over the last 3 seasons, is suspended by the NFL through week 9 and Glenn Dorsey, a run stuffer is injured and won’t return until the second half of the season.

Couple those losses with the fact the Niners had to replace nearly their entire secondary and this defense went from the filet mignon of the NFL to a quarterpounder at McD’s.

Meanwhile, the offense is undergoing a makeover that’s taking the classic run-heavy approach and transforming it into a high-flying, multi-receiver set air raid. Which would be fine, I guess, if Colin Kaepernick was at his best making decisions and reading his progressions through the defense. But he’s not. Kaepernick has regressed in terms of turnovers and is 2-5 when attempting 30 or more passes. He’s 16-2 when attempting 30 or fewer.

So great, go from the classic, fool-proof, running attack to putting the football in the hands of a quarterback who’s at his best when throwing less. What’s next, letting Miley Cyrus twerk all over the Mona Lisa?

Then there’s the lack of discipline. The Niners lead the NFL in penalties this year. In fact, in the 3 games, they’re averaging 12 penalties for 101 yards per game. In 3 years before, they averaged 6.7 penalties for under 60 yards a game. Big difference.

Between personnel moves and changing philosophy from everything that built success the past 3 years, the Niners are in a lot of trouble and could be watching as the rest of the NFL plays into February.

Julie Buehler hosts the Coachella Valley’s most popular sports talk radio show, “Buehler’s Day Off” every day from 3-6 on 1010 KXPS, the valley’s all sports station. She can also be seen every morning between 6-7am on KMIR sharing the coolest stories in sports. She’s an avid gym rat, slightly sarcastic and more likely to recite Steve Young’s career passing stats than American Idol winners. Tune in M-F 3-6 pst at www.team1010.com or watch “Buehler’s Day Off” on Ustream and KMIR.com for her sports reports.