Gore has put up some amazing seasons for the San Francisco 49ers over the years, despite the lack of success the team has had during most of his tenure. Gore has the most rushing yards, attempts and touchdowns in team history. Only Roger Craig has a better argument for being the team’s best running back ever.
However, Gore will be turning 31 in May. That doesn’t bode well for his continued production.
Only 23 times in NFL history has a running back ran for more than 1,000 yards in a season at age 31 or older. The average yardage for a player at age 31 hovers around the 640-yard mark; that would be a huge decrease off of Gore’s previous highs.
Gore has a cap hit of $6.45 million this season, seventh-highest in the league. It doesn’t seem very likely that Gore will be the seventh-best running back in the league next season, so there have been some calls for Gore to restructure his contract or even to be released.
On the other hand, head coach Jim Harbaugh has recently stated that he believes Gore has three good years left in him. Gore’s been productive for a 30-year-old running back; he has the tenth-most rushing yards of any back in their age-28 to age-30 seasons.
Could Gore buck aging trends and continue producing next season? Let’s take a closer look.
To get a good picture for Gore, we need to come up with a comparison for him.
It’s no good to look at all running backs in NFL history, because most players simply don’t match up—you end up looking at a bunch of career backups or injury-prone players.
Gore has done such a great job avoiding serious injury; he’s only missed one game in the past three seasons. Thus, it makes sense to compare him to backs who had a consistent number of carries in their age-28, age-29 and age-30 seasons. This will limit our comparison to running backs who got a decent share of the carries and weren’t coming off of a major injury.
There have been 77 players who have had at least 100 carries in each of those three seasons. Three were active last season: Frank Gore, Steven Jackson and DeAngelo Williams. That leaves us with 74 players we can look at, historically.
Longtime 49ers fans might remember some of the names on the list. Hugh McElhenny, J.D. Smith, Clem Daniels, O.J. Simpson, Wendell Tyler, Roger Craig and Charlie Garner all played for San Francisco in at least one of the seasons in question. Their age-31 seasons might go toward why some fans are hesitant to trust an aging Gore:
|Selected 49er Running Backs at Age 31|
|Hugh McElhenny||1959||San Francisco||18||67||3.72|
|J.D. Smith||1963||San Francisco||162||560||3.46|
|Clem Daniels||1968||San Francisco||12||37||3.08|
|O.J. Simpson||1978||San Francisco||161||593||3.68|
|Wendell Tyler||1986||San Francisco||31||127||4.10|
|Roger Craig||1991||L.A. Raiders||162||590||3.64|
Let’s break down the 74 running backs into groups, to look at the potential scenarios for Gore’s future:
|Qualifying Running Backs at Age 31|
|Carries||# of Players||Avg Yards||Examples|
|0||12||0||Barry Sanders, Michael Turner|
|1-100||22||136||Shaun Alexander, Larry Johnson|
|101-200||23||547||Priest Holmes, Willis McGahee|
|201-300||12||986||Ricky Watters, LaDainian Tomlinson|
|301+||5||1,550||Tiki Barber, Thomas Jones|
Of the 74 backs in the set, 12 didn’t receive a single carry in their age-31 seasons—a full 16.2 percent. Some likely could have gone on for longer, if they had wanted to. This group includes Barry Sanders, who shockingly retired after the 1998 season.
It also includes some players who tried to continue their careers but failed. Michael Turner is one of those players. Turner was released at the end of the 2012 season, and while he said he wanted to continue his NFL career, he ended up watching the last two seasons from the sidelines.
Assuming nothing bizarre happens and Gore remains on the roster for 2014, he won’t fall into this group.
A Shadow of Their Former Selves
An additional 22 players ended up notching less than 100 carries in their age-31 seasons, after topping that mark the previous three years—29.7 percent of the original total.
Shaun Alexander is the biggest of those names. In 2005, at age 28, Alexander was the NFL MVP, rushing for nearly 1,900 yards. Just three years later, he was ending his career in a Washington uniform, where he received only 11 carries as a midseason replacement as a backup.
Larry Johnson actually lasted two more seasons in the NFL, but he only picked up a combined six carries for four yards, sitting deep on the depth chart. He was actually cut in preseason, despite having a couple of 1,700-yard seasons on his resume.
Gore hasn’t been fading as fast as any of these players. The 1,128 yards he put up last season trumps any of their age-30 seasons. Barring an injury, it doesn’t seem at all likely that Gore would fall down this far.
Sharing the Load
Another 23 players hit triple-digit carries, but they didn’t reach 200. That’s indicative of a time-share in the backfield—usually as a change-of-pace for the undisputed starter or as the lead back in a three-back rotation.
We can use the 1978 San Francisco 49ers as an example here. They traded five picks over three years for the age-31 O.J. Simpson, who turned out to be a shadow of his former self. He did lead the ’78 49ers with 593 yards on 161 carries but ended up splitting carries with three other running backs. He nearly hit 60 yards a game, a far cry from his glory days in Buffalo.
Willis McGahee was in a similar situation in Denver in 2012. He was coming off of a Pro Bowl season but saw his number of carries drop from 249 to 167. He still led the Denver Broncos in carries, but Knowshon Moreno came back from injury to steal some. Furthering his issues, McGahee suffered a knee injury halfway through the season and was placed on injured reserve.
This feels like the most likely floor for Gore. It’s not hard to imagine him losing a step due to age or injury, while Lattimore steps up and takes more and more carries as the year goes on. A player in this bracket still can provide some value, but it would be a passing of the torch.
An additional 12 players stayed in the 200-carry range. Here, they’re still the featured back on their team, though other players are beginning to work their way into the lineup with a bit more regularity than a few seasons prior.
This ends up with situations like Seattle in 2000. Ricky Watters still ended up as a 1,200-yard rusher that season, despite losing nearly 50 carries. He was spelled more and more frequently by a rookie named Shaun Alexander, who took over the starting job the next season. This is the ideal outcome for the 49ers.
It also gives you situations like the 2010 New York Jets, where LaDainian Tomlinson, fresh off of being released by the San Diego Chargers, came in and formed a two-headed monster with Shonn Greene, with the aging back actually surpassing his younger competition.
This sort of situation would be why the 49ers are OK with Gore taking up so much of the salary cap—one last hurrah as a starting-quality runner, mentoring the young Lattimore to take over the starting role in 2015. It seems possible. Of the 12 players in question, only five had more rushing yards than Gore did in their age-30 seasons. Gore fits snuggly into this group.
Five running backs managed to top 300 carries in their age-31 seasons:
|Bucking the Aging Trend|
|Player||Age-31 Att||Age-31 Yds||Years Left||Yards Left|
Even with their great age-31 seasons, it’s important to note that only Payton and Dorsett continued having success beyond one last year—even a vintage season from Gore doesn’t necessarily mean he should be signed to a big contract after this year.
It would be something of a surprise for Gore to get this high; his age-30 season saw fewer yards than any of the five players named here. This is the pie-in-the-sky scenario.
So, what will Frank Gore’s numbers look like in 2014? There’s no way to be certain, but using math, we can come up with a guess.
Using a technique known as linear regression, I tried to find a way to predict a running back’s age-31 stats, based on his stats the previous three seasons.
It isn’t a perfect system, by any means. Some players vastly overplay their predicted amounts, such as Walter Payton, Curtis Martin and James Stewart. Others end up far below their expected totals, such as Barry Sanders, Earnest Byner and Michael Turner.
Still, the formulas explain somewhere between 40 percent and 55 percent of the variance, so that’s decent enough to take a look at the results.
I predicted the rushing attempts and rushing yards for Gore three times:
- Once using all 74 players in the sample
- Once using the 62 players who actually played in their age-31 seasons and
- Once using the 40 players who had 100 carries in each of the four seasons examined.
Call them the worst-, middle- and best-case scenarios.
Here are the results:
|Frank Gore at Age 31|
|All 74 players||195||785||4.03|
|62 active players||216||918||4.25|
|40 most active players||238||1,002||4.21|
Any of the three yardage totals would be Gore’s lowest since the 2010 season, when he missed five games with a hip injury. The lowest projection would be Gore’s worst total since his rookie season in 2005.
His carry numbers go down in every scenario, which makes logical sense—the team wouldn’t want to overtax Gore’s aging legs, and they want to see what Marcus Lattimore can do. Assuming the 49ers give the ball to running backs at the same rate they did last season, that would leave somewhere between 130 carries and 170 carries for Lattimore, Kendall Hunter and the rest of the backfield.
The numbers indicate that the era of Frank Gore as a Pro Bowl running back is likely over. That doesn’t mean he can’t still provide some value as the team shifts into uncharted waters at the running back position.
Stats are courtesy of Pro-Football-Reference.com unless noted otherwise.