Grant Cohn: Accuracy issues could slot Blaine Gabbert on 49ers’ bench

This is all you need to know about the quarterback competition going into the 49ers’ preseason game against the Broncos.

Even though he won’t play, Colin Kaepernick is the front-runner to be the Niners’ starting quarterback if he’s healthy and wants the job.

Why?

Because Blaine Gabbert is Blaine Gabbert. And Gabbert always has a problem with his arm slot. More on that in a moment.

We saw that Sunday when the Niners played their first preseason game against the Texans, and we’ll see it again Saturday when the Niners play their second preseason game against the Broncos. Gabbert is Gabbert.

He is a man defined by his past. Defined by failure. That’s who he is and always will be. He will not become Alex Smith, the quarterback most people compare him to. The quarterback who turned around his career and became a success, a winner. A Pro Bowler.

Smith and Gabbert have a lot in common on the surface. They’re big. They’re athletic. They have strong arms. They have quick releases. They’re smart. They can read defenses. They go through their progressions. They’re leaders. They work hard. They say the right things. They look the part of a franchise quarterback.

But Smith is a franchise quarterback and Gabbert never will be. Why?

Because Smith is accurate and Gabbert isn’t. That’s what it comes down to. When the ball leaves Gabbert’s fingertips, he has very little control over where it goes. Less control than Kaepernick, if you can believe it.

Every one of Gabbert’s passes is an adventure. Sometimes he throws over the top, sometimes he throws with a three-quarters release and sometimes he throws sidearm. He almost never repeats a throwing motion, or finds a consistent “arm slot,” as quarterback coaches say. For all of Kaepernick’s faults, he throws with a consistent arm slot. He’s a former pitcher. If a pitcher can’t repeat his throwing motion, he’s not a pitcher. He’s a designated hitter.

And if a quarterback can’t repeat his throwing motion, he’s not a starting quarterback. He’s Gabbert.

But why can’t Gabbert repeat his throwing motion? Why is he doomed to fail?

Two reasons. One, he seems like he has poor hand-eye coordination. Two, he almost never aligns his lower body with his target. This is his biggest sin. This is where arm slot becomes relevant.

Watch Gabbert’s legs and feet this Saturday. Watch the direction he points them, and then watch where the ball goes. You’ll notice they rarely go the same direction.

Gabbert is so confident in his arm-strength, he hardly uses his lower body when he throws. Mostly uses his arm. And halfway through his motion, his brain realizes his body lower body is out of whack and the ball is destined to go the wrong direction. So, in a millisecond, his brain tries to correct the path of his throwing arm which leads to a different arm slot every time.

That’s why Gabbert missed Carlos Hyde in the flat twice and completed only 4 of 10 passes against the Texans on Sunday. That’s why Gabbert completed only 55.8 percent of his passes his first five seasons in the NFL and just 60.9 percent of his passes in college. Mechanics. Accuracy. Hand-eye coordination. The most basic of the basics.

Kaepernick struggles with the graduate-level stuff like reading defenses, going through progressions and throwing with anticipation. But when he knows what he’s seeing and the picture is clearly defined for him, he can throw darts through the smallest windows. He’s extremely accurate. He proved that in the Super Bowl when he was 24 years old. Go back and watch. Refresh your memory. Gabbert never has made and never will make the throws Kaepernick made in that game.

Don’t get me wrong - I’m not saying Kaepernick is special or even particularly good. He was a disaster last season, he can’t stay healthy and his confidence seems shaky. He probably won’t be on the team next season. But he has to know he’s better than Gabbert. And Kelly has to know it, too. Even Gabbert has to know it. He watches the film. He sees himself throw those awful passes. Has seen it his whole life.

Keep your eyes on Gabbert this Saturday. If he plays against the Broncos the way he played against the Texans, Kaepernick could win the quarterback competition without even competing.

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.