One of the most improved units in the NFL the past month has to be the Cincinnati Bengals' offensive line.

Some of that has to do with the insertion of rookie center Trevor Robinson, who is a clear upgrade over Jeff Faine. But the real reason is the play of right tackle Andre Smith.

He has become a real force in the run game, and he's improved greatly in pass protection. The former first-round pick has been known more for being out of shape than his work on the field, but he has quietly elevated his game to a Pro Bowl level.

Smith was a mauler last week against the Chargers. Here are a few of his impressive plays to help spring BenJarvus Green-Ellis in the run game.

The first one below is a 41-yard run by Green-Ellis. On the play, Smith blocked down (yellow line) to help guard Kevin Zeitler on the double on the defensive end. But when Zeitler handled the end, Smith came off and got the key block on linebacker Takeo Spikes (blue line). With Smith sealing off Spikes, it created a nice lane for Green-Ellis to pop through for the big gain.

The next play shows Smith getting a great block on defensive end Vaughn Martin. He pushed him halfway across the field to create a lane for Green-Ellis. You can see by the two sets of hashmarks how far Smith drove Martin across the field.

Zeitler is having a heck of a rookie season next to him and the Bengals might have one of the better young right sides of any line in the league.

I mentioned Andy Dalton's horrible throw that led to Demorrio Williams getting a touchdown for the Chargers. For the life of me, I can't understand what Dalton saw. He is so much better than this throw. But take a look.

On the play, Dalton was trying to hit A.J. Green (red circle) on a slant route. But he never saw Williams (yellow circle) as he jumped underneath the route. It looked to me that Dalton thought he was against man coverage. Williams easily stepped in front of the throw and returned it for a score. That was uncharacteristic of Dalton, who usually makes smart decisions.

Kaepernick under pressure

The San Francisco 49ers' offensive line had a rough day last week against the Rams. That contributed to problems in the passing game. But for the second consecutive week, Colin Kaepernick did not take shots down the field when he had chances. That isn't to pick on the kid. I like him. He does a lot of good things. But at some point he has to let it go. The reason he's supposedly on the field is because of his ability to get the ball down the field.

The Rams played a lot of off-coverage, which seemed to affect the San Francisco offense. But there were a few chances down the field that Kaepernick passed up. On the first play, he had Michael Crabtree (yellow circle) running a curl route, but he had Vernon Davis (blue circle) down the field on a deeper route. It would have been a tough throw, especially with the corner bailing, but he had to make that read right away and get the ball out. If he had, he has a big play. It's the kind of throw the good quarterbacks make. But Kaepernick passed it up for a throw to Crabtree. There was a little pressure, but it came late.

Here's a second example. The 49ers motioned fullback Bruce Miller wide to the right (yellow circle) before the snap. He was outside of tight end Delanie Walker (blue circle), who was outside tight end Vernon Davis. Walker and Miller both ran go routes, which put pressure on the Rams defense. That left Miller wide open along the sideline but Kaepernick, who opened looking to his left, never saw him.

In fairness to Kaepernick, there was some pressure on those plays. But he is getting into a habit now of making his decision on where to go with the football before the snap. He didn't do that in the second half against the Rams in the first game when he took over for an injured Alex Smith. He has to get back to spinning his head.