We really thought Alex Smith was over his on-field problems, moving onward to the next level. Then comes a potential revenge game against the New York Giants at home, and the quarterback of the San Francisco 49ers implodes, throwing three interceptions on the way to a 3-26 loss.

Usually, the New York Giants need Eli Manning to have a big game in their wins. This time, jumping to an early lead in the second quarter finally gave the Giants an opportunity to run the ball effectively  with Ahmad Bradshaw running for 116 yards and David Wilson finally getting some carries, showing his talent when he’s not fumbling the ball.

The Niners defense is great, but there’s not much it can do when their quarterback turns the ball over three times. Eventually, the Giants’ running game pounded the best unit in the NFL into submission, gaining 133 yards between the tackles, the most the 49ers have allowed since week 11 in 2010.

The Giants haven’t allowed a 100 yard rushing performance by a running back in 22 consecutive home games, the last being Chris Johnson in 2009.

The last time Alex Smith (63.3%, 200 yards, 3 interceptions, 43.1 rating) was this bad, meaning throwing 3 interceptions?

The old Alex Smith, before Jim Harbaugh’s arrival, wasn’t new to these kind of games. It was the 7th time in his career that he’s thrown three interceptions, but the first since a 2009 December loss to the Philadelphia Eagles. All of his interceptions came on throws for more than 10 yards, which he was completing at 59.5% before this loss.

The 49ers system was built so Smith wouldn’t have to do complicated things. A great offensive line, great running crew and an elite receiving staff with Randy Moss, Michael Crabtree, Mario Manningham and Vernon Davis at tight end. The conception that he can do no wrong while all those parts around him work was proven, as the Giants shredded the offensive line.

The Giants don’t usually use more than four men in their pass rush, feeling so confident with their defensive line’s ability to dominate. Against the 49ers, it seems that their ability to change was a bit beyond the capability of Harbaugh to predict and adjust to, and way too much for Smith, who was sacked six times, hit three more times and saw six of his passes deflected.

When it comes down to it, Smith proved that despite the promising early numbers this season, he’s a system quarterback, on a close to elite team, but far from being an elite, or possibly even a good one himself. The game against the Saints in the playoffs last season? Looking more and more like a one-time thing. The real Alex Smith, the one that can’t convert on third down and can’t do anything under a little bit of pressure, showed his face in the loss to the Giants, which means that all the defense and power running in the world might not be enough to take this team to the Super Bowl.