For some NFL franchises, winning is simply a bonus when it happens. For others, winning is an annual expectation. And when the expectations aren’t met for the latter of the two, heads generally roll.

Such was the case for the San Francisco 49ers following the 2014 season. Even though former head coach Jim Harbaugh took the team to two NFC Championship games in his four-year tenure, including a Super Bowl berth two years ago, an 8-8 finish was enough for him to be cut loose.

The combination of a historically dominant defense playing below expectation and an offense that struggled to move the ball consistently were the main reasons why the team finished with a .500 record. Colin Kaepernick did not improve as a passer the way many had hoped he would, and injuries and suspensions took the punch out of the defense.

Entering the offseason, uncertainty surrounds the organization. But before we dig into that, let’s look back at 2014 -- what worked, what didn’t, and what the team needs to do to get back to the playoffs in 2015.

The Good

The 49ers defense, which has been the team’s strength over the last half-decade or so failed to reproduce its stingy play that we have grown accustomed to. As I alluded to in the intro, both injuries and suspensions played a large part in the defense playing under expectations.

Aldon Smith, who had accumulated 42 sacks in his first three NFL seasons and was quickly becoming one of the most feared edge rushers in the game, was suspended for 10 games in 2014, and the team certainly felt his absence. Navorro Bowman, one of the top inside linebackers in the league, missed the entire season with an ACL injury, and Patrick Willis, another stud linebacker, missed 10 games due to a toe injury.

The reason I’ve listed the defense here is because despite losing three of their top defensive players, the 49ers still finished 12th in total adjusted defense according to our metrics. They also finished 10th in points allowed per game (21.2). With everyone healthy and active, there’s no reason to think this wouldn’t have been another top defensive unit.

Shifting to offense, one of the only constants in 2014 was Anquan Boldin. At age 34, Boldin is defying the limits of age and is still a tough-as-nails wide receiver who consistently produces. He recorded his second consecutive season with at least 80 receptions and 1,000 yards and was far and away the 49ers best receiving threat.

From an analytical perspective, Boldin was 15th best in the league in terms of Reception Net Expected Points (NEP) per target among the 40 wide receivers with at least 100 targets (0.73), meaning that he gained 0.73 points for his team every time he was targeted. For reference, Boldin finished above both Alshon Jeffery (0.73) and A.J. Green (0.69) in this measure of true receiving efficiency.

The Bad

For the last few seasons, San Francisco was known for running the football and physically dominating opponents. In 2014, however, the 49ers ranked 21st in team rushing efficiency adjusted for schedule strength according to numberFire’s metrics.

Frank Gore, the model of consistency for nearly his entire 10-year career, again hit the 1,000 yard rushing mark -- his his eighth in his last nine seasons. And while no one can take away what Gore has done over his career, 2014 was not one of his best seasons.

His -0.06 Rushing NEP per attempt in 2014 was tied for the third-worst total of his career. It ranked him 40th among 60 running backs with at least 75 carries. And to top it off, he scored just five total touchdowns -- his lowest mark since 2010.

And while some hoped for more out of Gore, maybe the biggest disappointment on offense last season was the play of Vernon Davis. He struggled mightily almost all season, looking disengaged at times. He set career-lows in every receiving category (26 receptions, 245 yards, and 2 touhdowns) and really hurt the 49ers offense which was counting om his playmaking ability.

His analytics were downright atrocious as well. Davis ranked dead-last in Reception NEP (16.03) and Reception NEP per Target (0.32) among 27 tight ends with at least 50 targets, both of which set personal career-lows.

And finally we arrive at Colin Kaepernick. For someone who was believed to possess significant upside as a passer, Kaepernick finished the season tied with the likes of Kyle Orton and Brian Hoyer in terms of passing efficiency (0.04 Passing NEP per drop back).

And while some may point to his raw rushing statistics, which are impressive at face value, Kaepernick simply isn’t very efficient when he takes off to run -- ranking 10th last season among 13 quarterbacks with at least 30 carries in terms of Rushing NEP per attempt.

Moving Forward

Back in January, our own Joe Redemann discussed why the 49ers' decision to part ways with Jim Harbaugh was a big mistake. How will new head coach Jim Tomsula assimilate himself as the new man in charge?

The list of remaining questions for this organization as we move towards the 2015 season is pretty long, still.

Can Frank Gore still contribute to a running game that is going out of its way to get younger (see Carlos Hyde)? Will Aldon Smith even be in a 49ers uniform next season? And will Patrick Willis and Navorro Bowman be back to their old Pro-Bowl caliber selves when they return from their respective injuries?

As is stands right now, San Francisco still boasts a talented roster. But because of the uncertainty among the coaching staff, and the uncertainty surrounding a few key positions on the roster, for the first time since 2011, there appear to be more questions than answers in the Bay area.