Support this writer and shop Amazon

Identify the common thread. Singletary. Urlacher. Lewis.

Still not sure?

Willis. Bowman. Foster.

By now, fireworks should be going off in the heads of even the most casual NFL enthusiasts among us. These are linebackers. Specifically, these are middle linebackers. More specifically, these are star middle linebackers. Most specifically, and doubtless for San Francisco 49ers fans most tragically, the latter group are star middle linebackers who have, barring a miracle or three, hung up their red and golds for good.

It is a peculiar fact of 49ers history in the years since 2003 - a period best characterized as one vast post-season desert too briefly interrupted by a three-year mirage - that this organization has consistently boasted some of the most lauded middle linebacker corps in the game. Between 2011 and 2015, in fact, Patrick Willis and NaVorro Bowman ensured that such a claim was beyond dispute.

Like the post-Y2K legacy of these San Francisco 49ers as a whole, the tale of the middle linebacker has played out like a Shakespearean epic of surprise and intrigue, of hope and despair, of false allegations and concussions and bass fishing.

Patrick Willis was a superstar by any measure. Entering the 2007 draft with a two- season, 265 tackle, six-sack audition at Ole Miss under his belt, he was plucked by then-hapless San Francisco at eleventh overall. Patrick's early NFL career is best remembered as one half of a proficient dynamic he shared with famously intimidating veteran Takeo Spikes. Nothing encapsulates the ferocity of that three-year collaboration quite like the image of both men sporting matching casts - or clubs, if you were unfortunate enough to be an opposing quarterback in 2010 - on their right hands. Toughness and resolve were the spirit of the day.

For Mr. Spikes, that day ended after the 2010 season, not-at-all-coincidentally the same year his team selected Penn State middle linebacker NaVorro Bowman in the third round of the NFL draft. After a relatively nondescript rookie season was spent getting his professional bearings, Bowman dedicated his sophomore campaign to revealing himself as much more than an ample replacement for the departed veteran.

The argument could and has been made that Bowman's proficiency from that season on may even have matched his partner in the middle, although comparing any modern defender to Patrick Willis is so brazen as to demand thorough statistical analysis. Below are side-by-side assessments of two side-by-side careers. Warning - reminiscing about the good old days may lead to frustration and has been shown to induce high blood pressure.

Patrick Willis: taken eleventh overall in the 2007 NFL draft, retired before the 2015 season. According to Pro Football Reference, through 112 games started he amassed 950 combined tackles, 20.5 sacks, sixty tackles-for-loss, forty-one quarterback hits, sixteen forced fumbles, eight interceptions, and two touchdowns for good measure. Garnering the most solo and combined tackles in the National Football League during his first (2007) and third (2009) seasons, Willis proved he could bounce back from a disappointing sophomore campaign (2008) that saw him attain only second place on those lists. Through eight seasons, Patrick Willis was selected to seven pro-bowls and five All-Pro teams.

NaVorro Bowman: taken ninety-first overall in the 2010 NFL draft, released by the 49ers at his request during the 2017 season. After one season with the Oakland Raiders, he is currently a free agent. According to Pro Football Reference, through eighty-four starts across ninety-nine games, he amassed 798 combined tackles, fourteen sacks, forty-eight tackles-for-loss, thirty quarterback hits, nine forced fumbles, and a particularly memorable eighty-nine-yard interception return for a touchdown. After twice placing second in total combined tackles among all defenders, he finally topped the list in 2015 with 154. Through eight seasons, Bowman was selected to three Pro Bowls and four All-Pro teams.

Suffice it to say that this level of productivity is uncommon at any position in football. To have two recurring All-Pro linebackers sharing the field for four seasons is nothing short of a statistical aberration. It is no accident that for the 2011, 2012, and 2013 seasons - a three year stretch during which both men started and remained relatively healthy - the 49ers won thirty-six regular season games to eleven losses, ultimately attending three NFC Championship bouts and one ill-fated Super Bowl.

Despite the Super Bowl loss, it seemed that the special linebacker duo and their strong-willed, strong-chinned head coach were well positioned to fulfill the promised quest for a sixth ring. But like all good things must, and, for the San Francisco 49ers, all good things did - that promise came to an abrupt halt in the 2015 offseason.

Like Achilles with his heel, demigod of the football world Patrick Willis was undone by a lacerated toe. The 2014 season represented a fall from grace for the darling of northern California. It was a season he only participated in peripherally - limited to six games by the nagging cut on his toe, and so producing hardly a fraction of his former numbers. Between fiery pre-game speeches and locker room consolations, ten weeks on the sideline provided Willis ample time for reflection, and the end result was a decision to withdraw from the NFL and from the organization that so adored him.

Wistful scrolls through his Instagram page in the years since reveal that Patrick does not regret his decision. His retirement is spent on aluminum boats, fighting any bass to cross his path for short and impassioned moments, a flash of excitement amidst hours of waiting and wondering. When at last he releases his catch, the fish, like 49ers fans, can be sure to swim away bewildered by the wildly peculiar event it had been subjected to, and puzzled most of all by the way it had ended.

Even before Willis' retirement was set in stone, it seemed the 49ers might already have had a potential replacement waiting in the wings. Through eight starts and six games in a supporting role, Chris Borland revealed a surprising potential to pick up where his legendary predecessor left off. It is impossible to forget, however, that the rookie's flash-in-the-pan success also coincides with the transformation of San Francisco's linebacking story from triumph into tragic and unrelenting parody.

After his 107 tackle and two interception effort, both totals which are beyond respectable considering his abridged snap count that season, Chris Borland was placed on injured reserve for an ankle injury in the waning weeks of December 2014. Despite having his season curtailed, Borland provided some much-needed reassurance for Niner fans reeling after Patrick Willis' retirement announcement on March 10th the following year. The faithful had only one week to recover from that gut punch before Chris Borland announced that his intentions were the very same. Having suffered two diagnosed concussions throughout adolescence and convinced he'd added as many as thirteen during his sole season in the National Football League, Borland stepped away from the sport for the sake of his health.

NaVorro Bowman remained a beacon of hope tucked between unfamiliar names on a shell of the 49ers once enviable roster. That was, of course, until he was not. One offseason removed from an All-Pro, combined-tackle-leading 2015 campaign, the second of two Achilles tears Bowman would suffer as a 49er would constrain his 2016 season to four starts. Two full seasons and as many head coaches after Patrick Willis' departure, Bowman was released just five games into the Shanahan-Lynch era in San Francisco.

In the all-important realm of the middle linebacker, what are we left with? Better put, what were we left with? By the end of Kyle Shanahan's inaugural season as head coach, all signs pointed to promising 30th overall selection Reuben Foster. Plagued from the outset by off-the-field shenanigans in the style of Aldon Smith, as well as a Gronkowski-esque knack for plastering his name all over the weekly injury report, Foster nonetheless demonstrated a head for the game and a nose for the ball fit to serve as the next great 49er MLB. So appreciable was his upside in proportion to his record questionable behavior at the time that the John Lynch-led front office actively traded back into the first round to snag him.

That ratio would change quickly and dramatically during his two-year stint with the franchise. Offseason possession charges, be they marijuana in Alabama or guns in California, dampened the general excitement that followed his rookie campaign. Though suspension loomed, rectification for the young Crimson Tide alum seemed possible through repentance, and the hopes of 49ers fans still rested on Reuben's punishing, if not injury-prone, shoulders. Even allegations of domestic abuse did not altogether diminish his opportunity to produce for the team that had drafted him - at least not the first time.

Nearing the middle of a 2018 season which seemed to deliberately conspire against those fans who dared enter preseason with a shred of optimism, perhaps the only cause for hope was, once again, an exceptional pair of middle linebackers. Reuben Foster, acquitted in court of the most egregious of his alleged offenses and so allowed by the NFL authority to return after serving a suspension, joined forces with 70th overall selection out of BYU, Fred Warner. Warner proved an immediate starter and veritable asset. While consistently overproducing in tackles (124 total) across a full docket of starts at middle linebacker, he conspicuously underproduced in injuries and incidence of personal debauchery relative to his counterpart in the middle. Hopes were high that Warner would double as a good influence and good incentive for Foster to get his act together and shore up an ailing defense.

And so the parody continues. Just as the first chutes of optimism were sprouting from the layers of topsoil formed by departure after unceremonious departure, the heart of San Francisco's defense would suffer another blow - and dreams of a new dynamic linebacking duo would be destroyed, root and stem. Hours before a lackluster outing against the Buccaneers and mere weeks returned from suspension, twenty-four-year-old Reuben Foster was arrested at the team hotel in Tampa. Less than two years removed from his first-round selection by San Francisco, locker-room-culture hardliners in a dozen front offices were at last vindicated for passing on the troubled prospect, and retroactive draft-grading pundits rejoiced over the gift of new material.

As another offseason trickles by at an agonizing pace, we are faced, again and all too soon, with a familiar question - what are we left with? I would not blame anyone on the receiving end of that question for opting to bite their tongue. It's hard to be optimistic, and harder to stay that way if you're a 49er fan with a memory that extends beyond the last twenty minutes. If they do choose to answer, though, they will no doubt invoke the seemingly bright future of Fred Warner. It should come as no surprise. I fall into that camp myself.

Perhaps he'll enjoy a long, healthy, productive career. Perhaps we'll enjoy it right alongside him. Or perhaps it will go the way of Patrick Willis - a flash of brilliance that might have gone on, if not for a toe. Perhaps it will go the way of NaVorro Bowman - years of greatness disjointed by catastrophic injury. Maybe he'll see the football world from Chris Borland's perspective, a cherished experiment that ultimately isn't worth the risk to his health. The least that can be said for young Fred Warner, impressive a rookie middle linebacker as he was, is that he represents the uncertain future of a franchise draped for decades in one incredulity-inducing misfortune after another.

Though there is certainly no sign that Warner will go the way of Reuben Foster, the future, with all its delicate promises, all too often shows us that any position group so inclined to flying close to the sun will produce no shortage of surprises - good ones or otherwise.