The 49ers beat the Broncos 29-24 but the 49ers were awful when it counted, as in disastrous, as in painful on the eyes.

Be clear about that. The third exhibition game is close to being a real game. The vast majority of coaches game plan for the third game, although it's unknown if Jim Harbaugh game planned. When asked if he would game plan, he ducked the question like someone avoiding an incoming rocket, the usual maneuver for him. He never met a question he didn't duck.

But he kept his starters on the field for most of the first half, and his starters — let's find the correct technical word for this — stunk. Yes, that's it. The starters stunk.

Peyton Manning absolutely shredded the vaunted Niners defense, and if the Niners do not have a defense, well, what do they have? But, frankly, it's not the defense's problems that are of interest at this moment. The defense almost surely will come around when Aldon Smith returns. The offense is a whole other story.

Let's start with a few statistics comparing and contrasting the Denver and San Francisco attacks. With Manning leading the offense in the first quarter, the Broncos converted two of three third downs. Manning also threw two touchdowns in the red zone. That is very good. We'll get back to Manning in a moment because he is a very sore subject for 49ers general manager Trent Baalke.

In contrast to Manning, Alex Smith, the Meek and Mild, converted one of four third-down opportunities and was unsuccessful on his one try from the red zone. One assumes he would have been unsuccessful if he had more tries from the red zone because that is what he does — or doesn't do.

In his one pass attempt from the red zone early in the second quarter, his protection broke down, as usual, whereupon he backpedaled and threw the ball away, as usual. The backpedal and throwaway are Smith's signature moves in the red zone and it's comforting to see he already is in midseason form.

Why is the offense's floperoo in the red zone a concern? Oh, that's simple. 1) It's always been a problem with the current bunch and nothing seems to have changed. 2) Knowing it's a problem, you would assume Harbaugh and his brain trust would have made correcting it a point of emphasis in the preseason. So, where's the emphasis? And while we're at it, where's the improvement?

Let's be blunt. The Niners' offense we saw in the first half is cause for alarm. Like the one deep pass Smith threw to Randy Moss. Of course, it was overthrown as in incomplete, as in no clue. Perhaps, the 49ers are hiding some secret plan with Moss for two weeks from now in Green Bay. Or perhaps Smith has achieved zero chemistry with Moss in the preseason, when he has the luxury to work on that chemistry. We'll see.

The 49ers got all the breaks last season — especially on defense — and no team gets all the breaks two seasons in a row. Harbaugh might want to improve his offense's performance on third down and in the red zone. He probably knows that already. If Harbaugh is smart, he'll claim he did not game plan his offense in Denver. No one would want ownership of what the 49ers did in the first half. Near the end of the half, Terry Bradshaw described the San Francisco offense on television. "This doesn't look good," he said.

Now we come to the main point of all this — Manning vs. Smith. Early in training camp, Harbaugh made a point of telling the media, whom he called phonies, that the 49ers did not try to sign Manning even though Harbaugh secretly traveled across the country to watch him work out. Harbaugh said he merely was inspecting the goods, Manning's goods. This fact we know — after Manning signed with Denver, the 49ers made Smith a contract offer. Coincidence? You make the call.

But, OK, let's give Harbaugh and his pal Baalke the benefit of the doubt. They are innocent of ever wanting Manning. That doesn't exactly make them not guilty. If you watched Sunday's game, you know Manning is a better quarterback right now than Smith. You know he is better than Smith ever will be. You know he will make the Broncos a contender in the AFC West and you know — come on now — he could lead the 49ers' offense better than Smith.

What's the point? The 49ers should have signed Manning and dumped Smith. But John Elway and Denver signed Manning. If the Niners do worse this season than last, it won't be because the defense is bad. It will be because of one thing only: Smith is not Manning. The Niners are guilty of not signing Manning.

For more on the world of sports in general and the Bay Area in particular, go to the Cohn Zohn at cohn.blogs.pressdemocrat.com. You can reach Staff Columnist Lowell Cohn at lowell.cohn@pressdemocrat.com.