It started, of course, with "unfinished business."

Against the Giants, said a dimwit predictor, the Niners had "virtually every advantage." After throttling the Jets and Bills, we seemed to have retaken our place atop the league. And though the Vikings had sprung a deflating trap, we'd had the Giants circled for months. No one needed any incentive, any reminder of what they'd done. With a big assist from one of our own, they'd ruined everything; and instead of thanking their lucky stars, they'd dared to think they were better than us.

The conditions were perfect for proving 'em wrong. We had all the confidence, all the momentum, all the purpose of "unfinished business."

But here's the thing about "unfinished business." Sometimes, it finishes you.

It should first be acknowledged, the Giants are good; and with a league like this, where good teams lose to bad every week, losing to good is not a big deal. So we needed to guard against overreaction. Oh, sure, our D again showed a tepid pass-rush, and now it was gashed with some serious runs; but just as they had in the title game, the Giants scored half their points by starting drives from the Niners' end. And yeah, our special teams again were loose—which forced us to question some offseason moves—but surely our coaches could tighten 'em up.

So there was no cause for overreaction. Yet just as much, underreaction would be a mistake. This was a team-wide, collective malaise, the second such malaise in a month. Given Jim Harbaugh's relentless intensity, and given the Niners' stakes for this game, this laying of egg was deeply unsettling. But naturally, the unsettlement focused on one man, from whom we simply can't escape.

Because it had been so long since Alex Smith had lost us a game—as his three interceptions certainly did—it was tempting to dismiss the Giants game as merely aberrational. But perhaps the Bills game was the true aberration. Indeed, leaving that game aside, Smith's rating had dropped in every single game this year, from 125 to 43. So the Giants game simply continued a trend, a trend of inexplicable regression.

Oh, did I say inexplicable? For the Smitheists, there's no such thing. Hence arose an all-new round of Alexcuses, the main one being the "disruptive" injections of Colin Kaepernick. Smith just couldn't get into a "flow," or so this newfound theory went, because of his backup's haphazard appearances. This theory, though, didn't make any sense. Even assuming that a lack of "flow" induces a quarterback to make dumb decisions, it's unclear why going to the bench for a play—as opposed to, say, handing off to a halfback, or even sitting between series—is so disruptive to the quarterback's "flow."

Nevertheless, Harbaugh went along with this theory, suggesting that Kaepernick would be kept largely on ice, against Seattle on Thursday night. In the wake of the Giants, this was now a huge game. A loss would be our second-straight (and second-straight at home, no less), but also would drop us to third in the West. As far as games in October go, this was about as must-win as they get. And though Harbaugh had his doubts about Smith—this was why he'd begun using Kaepernick in the first place—Smith would get the chance to win it.

Despite much talk of Seattle's supposedly stingy D, it hadn't much bothered Tom Brady, who'd racked up nearly 400 yards (though he'd thrown two picks to go with two scores). Yet during a first half that was as bad as anything we'd seen on Sunday—or ever, for that matter—Smith threw for 59 yards. It's not as if his receivers were open on every play, as Seattle's coverage was borderline-illegal, but Smith still had his chances and missed. (It goes without saying that Smith did nothing to "throw his receivers open," which he's utterly incapable of doing.) By halftime, after three straight three-and-outs, the Niners had gone six quarters without a touchdown.

At that point, Harbaugh had seen enough. He didn't go with Kaepernick, who truly must not be quite ready (though it's hard to see how he could've done worse). Instead, he just gave up on a big-boy O. New plan, he said, and Smith became like a rookie again; checking down was his only read. Perhaps shocked by the transparency of our meekness, Seattle was actually caught off-guard, and Smith dinked and dunked all the way to the end zone. But on our next drive, on third-and-goal, looking for the touchdown to put it away, Smith came back with his worst play ever: Randy Moss set up camp in the back of the end zone—so incredibly open that Frank Gore actually pointed to Moss—yet Smith didn't see him until it was too late.

Of course, that interception—which matched Smith's total for all of last year—happened only because, on the previous play, Kaepernick had disrupted Smith's "flow." Yeah, that's it.

Smith threw only one more pass the rest of the night, predictably a three-yard checkdown. On a red-zone third-and-seven, still needing a touchdown to ice the game, Harbaugh called a Smith keeper and took the field goal. And later, on a third-and-eight, now needing a first down to ice the game, Harbaugh did it again and punted away.

He trusted Smith to do nothing more. In other words, he trusted Smith to do nothing at all.

After our D put the game away—despite another spotty performance—Harbaugh joined the excuse parade, implying that Smith was struggling with the middle finger he'd sprained against the Bills. Yet against the Giants, he'd thrown a perfect 50-yard bomb; he didn't seem to be struggling then. Though Smith's accuracy will never win any awards, he's struggling with his decisions, not his hands. So enough already, with all the excuses. He's got his offensive head-coach. He's got his good receiving-corps. He's got his second year in one system. There aren't any excuses left. All that's left is Smith himself.

For years it was always the great unknown: how truly good is Alex Smith? Well, now, we finally know. We know his ceiling, and he's already there. He's certainly capable of great plays, great drives, even great games now and then. And it's still true, he seems to come back strongest when you're doubting him the most. (So we can safely predict that he'll go for 350 against Arizona.) But forget about that consistent explosiveness. The most we can ask is consistent efficiency, and lately even that's been too much.

Of course, this could still be enough, for a fine season, a division title. But we're talking about the Super Bowl, the only goal that matters here. And since the opening day of training camp, that goal has turned on a simple equation. If the defense regressed, Smith would need to make up the difference. Only then would we have a real shot, a genuine chance at winning it all.

Though it's still quite good, the D has regressed. But Alex Smith has regressed even more.

As much as it hurts, you do the math.