INDIANAPOLIS -- Because we have all seen what Brandon Jacobs can be when he's at his best, it is uniquely disappointing when he is not. At 6-foot-4 and 265 pounds, Jacobs is supposed to be a terror with the ball in his hands -- an unstoppable, line-shredding force that defenders fear to tackle. Too often over the last couple of seasons, for one reason or another, he has failed to perform that way consistently. The criticism he takes for it works off the expectations created by his uncommon physical attributes. He's so big and scary, so why can't he always play that way?

In the days leading up to Super Bowl XLVI, Jacobs seems to feel the same way about himself that others feel about him. This could very well be Jacobs' last game with the New York Giants, and he knows that. If his head is in the right place, as it appears to be, Jacobs could end up being a surprise Super Bowl difference-maker.

"I've just got to run a little harder," Jacobs said Wednesday. "I felt like, in the last game, I ran ... OK, I guess. I've just got to run a little harder and try and get more yards after the contact. If they're a good defense, then you're going to get hit, so you may as well get ready for it. I've just got to get going a little harder and try and get a couple extra yards."

Jacobs has been a mercurial player for the Giants over the last few years. His off-field behavior and on-field effectiveness have fluctuated between maddening and exemplary. He's the guy who chucked his helmet into the stands in Indianapolis, who chased down Jets coach Rex Ryan on Christmas Eve with a "time to shut up, fat boy." He has seemed, too often, like a guy to whom football isn't that big of a deal.

But he's also the guy who agreed to restructure his contract last summer so the team could re-sign his friend and fellow running back Ahmad Bradshaw, who accepted a demotion two years ago when it became clear Bradshaw had become the better back, and who dished out punishment while he and Bradshaw ran all over the Atlanta Falcons four weeks ago in a dominant playoff performance.

"I always feel like Brandon is about to have a big game," Bradshaw said. "He's just that kind of guy. When he gets going, there's no one out there that can stop him, and we've all seen that."

Jacobs remains, however, a source of frustration for Giants fans. He's supposed to be a bulldozer who can pick up automatic first downs on fourth-and-1, yet he seldom seems to be able to get them. He's supposed to be a goal-line stud, but sometimes it looks like he's trying to tiptoe through a hole rather than just blow one up. To a certain extent, the criticism is unfair. Just because he's more huge than the typical running back doesn't mean he's supposed to accept getting hit more. Jacobs' size is his burden as well as his asset, and he has expressed frustration with that criticism.

But he's reached the point at which public perception can no longer matter to him. He's got one year left on his Giants contract, but there's a chance the team will cut him and move on, deploying that money elsewhere and working on the development of their younger backs. That means Jacobs, who won a Super Bowl ring as the Giants' lead back four years ago, might have only one more game left with the only pro team he's ever known. And there's no reason to do anything other than play it as hard as he possibly can.

"I can't worry about that," Jacobs said when asked about his Giants future. "I hope not. I want to be here. I want to be around. But right now, I just want to come out here and win this football game. After that, whatever happens happens."

A focused Brandon Jacobs can be a scary thing for an opposing defense. If the big guy has one more big Giants game left in him, there's a good chance he leaves New York with two Super Bowl rings. Which wouldn't be a bad way to go out.