Grant Cohn: Why Anquan Boldin isn't back in a 49ers uniform

Why haven't the 49ers re-signed Anquan Boldin?

The question probably crossed your mind. Probably crossed Boldin's mind, too. He's a free agent waiting for a team to make him an offer. Why wouldn't that team be the Niners? Why haven't they tried to sign him?

Without Boldin, the Niners have the worst group of receivers in the NFL. The projected starters are Torrey Smith, Quinton Patton and Bruce Ellington in the slot. Combined, those three caught 76 passes last season. Boldin caught 69 by himself. He was by far the Niners' best, most reliable receiver, especially on third downs.

Last season Boldin caught 19 third-down passes, while Smith caught seven, Patton caught 10 and Ellington caught just three. Which one of them will take Boldin's role as the 49ers' go-to third-down receiver?

None of them can do exactly what Boldin does. Boldin gets open by barreling into defenders and bouncing off of them — call this the bumper-car method of running routes. And once he catches the ball, his hands are Velcro. He's an all-time great third-down receiver.

I'm guessing the Niners would have re-signed Boldin by now if Jim Harbaugh still were the head coach. Harbaugh wanted tough players at every position and Boldin is one of the toughest players ever. He's the Platonic ideal of a Harbaugh Receiver. Harbaugh loved him.

New 49ers head coach Chip Kelly values quickness and speed over toughness. Kelly is the anti-Harbaugh. Which means he has no use for Boldin. And that's why the Niners probably won't re-sign him.

Boldin never was quick or fast, and now he's 35 — he'll be 36 in October. He's slower than ever. And he doesn't change directions well, either. He crashes into people. That's his move. Kelly doesn't have that move in his playbook.

If you get a chance, watch video of Kelly's offense when he coached the Philadelphia Eagles. That's the offense the Niners will run next season. You have to know Kelly's offense, especially his tendencies on third down, to understand why Boldin is gone.

I'm talking tendencies on third-and-medium, third-and-2 to third-and-6 to be precise. On these downs Kelly almost always calls the same kind of pass. It's what coaches call a 'people play,' meaning the pass is intended for just one person. There is no 'pattern' or 'progression.' The quarterback catches the ball, stares at one receiver – usually the slot receiver — and waits for him to get open. The receiver usually gets open quickly.

How does he get open quickly? He runs an 'option' route, meaning he runs to the first-down marker ('the sticks' in football language) and cuts sharply to the left or right depending on how the defender is covering him.

Harbaugh did not use option routes. He removed them entirely from the 49ers' playbook to keep things simple and minimize interceptions. Because when option routes fail, the receiver usually cuts one way, the quarterback throws the other way and the defense picks him off. High-risk play.

Kelly loves option routes. Because when they succeed, when the quarterback and the receiver read the defense the same way and the receiver changes directions quickly, option routes are extremely tough to defend.

To make them even tougher to defend, Kelly has a second wide receiver run a deep route on the same side of the field. So if the defense tries to take away the receiver running the option route at 'the sticks,' it will give up a long touchdown catch to the receiver running deep.

That's Kelly's go-to pass concept on third-and-medium. Watch the video — you'll see him use that concept almost every time. It's central to his offense.

Boldin can't execute that concept. Doesn't change directions quickly enough to run an option route or sprint fast enough to run a deep route. Not at his age.

Smith will run most of the deep routes on third-and-medium and Ellington will run most of the option routes. Little Bruce Ellington, the punt returner. He specializes in changing directions and catching the ball in traffic, so he fits Kelly's offense perfectly.

Ellington is Kelly's replacement for Boldin, Kelly's go-to receiver and the player to watch during training camp and preseason. You probably didn't see that coming. Boldin probably didn't, either.

Grant Cohn writes sports columns and the 'Inside the 49ers' blog for The Press Democrat's website. You can reach him at grantcohn@gmail.com.