49ers vs. Rams preview: Frank Gore winning longevity battle with Steven Jackson

On Sunday, the San Francisco 49ers will take on the St. Louis Rams in their third-straight NFC West tilt. There's few things that have been a constant for these two teams over the past several years, with changes to the head coaches, coordinators, quarterbacks, receivers and so on and so forth. But one constant has remained: Pro Bowl-caliber running backs in Steven Jackson and Frank Gore.

Over the years, Gore and Jackson have been great players sweating it out for bad teams. There's not a nicer way to put it, and it wouldn't be exaggerating at all to suggest that those players had their primes wasted on teams that were always going nowhere. That's just the way it works sometimes (Hi, Maurice Jones-Drew!) in the NFL.

But which running back has been better over the years? Well, if you look at the yardage totals, you'll see that Jackson has generally had more than Gore, but on the yards per carry stats, Gore generally is ahead, sometimes by a large margin. You'll also notice that Jackson has carried the ball about 500 more times than Gore, including 100 more times than him in 2009 alone, when Jackson had 1400-plus yards.

You can make whatever arguments you like over who has been better, but it's clear that Jackson was counted on much, much more than Gore, something that seems an oddity to say when you don't give it too much thought, given how much this franchise has made Gore into the bell-cow.

There's one argument that I'm OK with making right now though: Gore is better in 2012, and he's got more time left. St. Louis' propensity to ride Jackson into the ground has caused him to suffer a steep decline in productivity this year, and he's on pace for career lows in just about everything, especially is you discount his rookie season.

Now, it's true that Jackson's carries are dropping off a lot, as the Rams try to put the game in Sam Bradford's hands in true "trial by fire" fashion, and running back Daryl Richardson is making his case for more carries. But the thing to note is Jackson's per carry average, which is dropping down each time out.

In short, when he does have the ball, he doesn't look good. He doesn't look the same running on film and the stats corroborate. Jackson is slowing down and there's nothing to suggest otherwise.

Gore, on the other hand, is rushing for 5.5 yards per carry this season, and his on his way to another 1,000-plus yardage total on the season. Gore looks great right now, in fact. People thought he might be slowing down just a hair last season, but he's not showing any of those signs this season, and heck, he might just be good for a couple more.

None of this means that Jackson is somebody the 49ers can overlook on Sunday. It doesn't mean that he can't break out and have a great day and make us all look bad. It simply means that he's not one of the big keys to the game, and it's an interesting factor for a rivalry that has only had its duel of running backs to talk about as a constant over the years.

Jackson has the yardage but Gore, remarkably, has the longevity.