QB matters most, with or without Crabtree

While losing Michael Crabtree will surely hurt the 49ers, it will be Colin Kaepernick's play that will determine San Francisco's success. Harry How/Getty Images

The San Francisco 49ers, though unusually healthy in recent seasons, had a hard time recovering from injuries to return specialist Ted Ginn Jr. and top defensive lineman Justin Smith over the past two seasons.

Bill Barnwell drives home that point in his latest piece for Grantland, one calling into question how the 49ers will recover from Michael Crabtree's injury.

2012 Michael Crabtree Receiving

The piece also touched upon a subject we've discussed in some detail around here: Crabtree's improved production with Colin Kaepernick at quarterback.

"Crabtree and Kaepernick, they have that swagger," Jerry Rice observed during Super Bowl week. "It's how they go out, how they play, the energy on the football field. If they are making plays, Crabtree is always talking noise at the defender or something like that.

"You can see the swagger; you can see the confidence."

Thanks to the chart, you can see Crabtree's production spiking when Kaepernick, not Alex Smith, was the one targeting him. Kaepernick attempted 298 passes last season, counting playoffs. Smith attempted 218 passes, all during the regular season (Kaepernick also had 218 regular-season attempts). The increased production for Crabtree was about more than additional opportunities. It was about Kaepernick and Crabtree maximizing them.

Crabtree's injury hurts, no question, but quarterbacks are far more important to overall team success. That is what the information in the chart is telling us.

Kaepernick, not Crabtree, remains the key for San Francisco. He was the key to unleashing Crabtree. He will be the key to maximizing other weapons as well.

As Barnwell notes, Anquan Boldin's playoff production for the Baltimore Ravens wasn't representative of his production with the team previously. We might naturally assume that Boldin, now with San Francisco, won't produce those kinds of numbers with the 49ers. We might logically expect a regression.

However, the change in Boldin's production during the postseason reflects dramatically improved play from quarterback Joe Flacco, who had been ordinary until the postseason. Flacco posted a 46.8 Total QBR score during the 2012 regular season. That was below the 50-point average for NFL quarterbacks. His regular-season QBR since 2010 was only 55.4, barely above average. The figure rocketed to 83.6 during the most recent postseason, indicating Flacco suddenly began playing at an MVP level.

Kaepernick's QBR score was at 76.8 during the regular season and 86.5 during the playoffs.

So, unless Kaepernick suddenly turns into what Flacco had been previously -- an average starting quarterback -- the 49ers should be able to get more from Boldin than the Ravens got from him during most of his tenure with the team.

Maintaining the pace Boldin set during the playoffs could be unrealistic, but an improvement from his regular-season stats sounds reasonable.

We should also expect the relationship between Kaepernick and tight end Vernon Davis to grow, especially without second tight end Delanie Walker siphoning off receptions periodically. Davis' rapport with Smith was well established. There's no reason Kaepernick and Davis can't build something similar, particularly now that they know their relationship is more important than ever.

Davis had three 100-yard receiving games last season. Two came during the playoffs, both with Kaepernick at quarterback. Kaepernick was the 49ers' quarterback for three of the four games in which Davis had at least 75 yards receiving.

Elsewhere in the division last season, we saw Russell Wilson get the most from Sidney Rice and Golden Tate, who had previously been underwhelming for Seattle. We saw Larry Fitzgerald's production slip with third-string quarterbacks in the Arizona Cardinals' lineup.

Every organization dreads serious injuries. Sometimes, the personnel people working for the really good ones get excited when an injury opens the way for unproven players to get an opportunity.

The 49ers will find out this season what 2012 first-round receiver A.J. Jenkins can offer them right now. They'll get a look this offseason at Ricardo Lockette, a player coach Jim Harbaugh thinks has a future in the league. Rookie fourth-rounder Quinton Patton might get a shot, too.

On the bright side, Crabtree could return from his torn Achilles' tendon late in the season.

The 49ers could consider veteran help in the interim. I would not expect them to panic. Re-signing Randy Moss wouldn't make a great deal of sense in the bigger picture, for example. He's old, declining and doesn't fill the role Crabtree filled on the team. Some of the 49ers' thinking could depend upon where Mario Manningham stands in his recovery from knee surgery.

Crabtree was important. The 49ers' other receiving targets are important. The margin for error has diminished for San Francisco. But we shouldn't lose sight of what matters most. Kaepernick is the key. Quarterbacks almost always are.