Derick E. Hingle-USA TODAY Sports

It was there for the taking. For more than fifty minutes, the Oakland Raiders gave Philip Rivers and the San Diego Chargers more than they could handle. And with less than five minutes to go, they were in a position to claim their first victory of 2014 over the AFC West leading Chargers. But in a scene that has become all too familiar, the Raiders defense yielded the go-ahead touchdown, thus snatching defeat from the jaws of victory. Again.

Dennis Allen took the fall for Oakland’s many failures and shortcomings over the past three seasons. And while cutting ties with Allen was the right decision given the fact that not only had the team not shown any improvement during his tenure, but actually seemed to regress this season. But DC Jason Tarver should bear a substantial amount of the blame for Oakland’s lack of success.

When Tarver joined Allen’s coaching staff in 2012, he was touted as having one of the most creative and innovative defensive minds in football. He was labeled the “mad scientist” not just for his degree in biochemistry, but for allegedly having a playbook filled with exotic schemes and blitz packages. 37 games into his tenure as Oakland’s DC though, and we’re still waiting to see some trace of the defensive genius Tarver was purported to have. Over Tarver’s tenure, we’ve seen an Oakland defense that ranked 28^th in 2012, 29^th in 2013 and is 26^th thus far in 2014.

To be fair, in Tarver’s first two seasons, Reggie McKenzie was just beginning his “deconstruction” phase of Oakland’s rebuild and the roster was lacking talent. But 2014 saw veteran talent like Justin Tuck, LaMarr Woodley, Tarrell Brown, and Antonio Smith joining with explosive young playmakers like Khalil Mack, Sio Moore, and TJ Carrie. Tarver was handed a roster loaded with talent. And yet his defense still dwells at the bottom of the league.

For much of the game against San Diego, it looked like perhaps the defense was turning a corner. Tarver had dialed up some blitz packages and was giving the Chargers some different looks. Philip Rivers had defenders in his face all day long and San Diego was back on their heels. Oakland was in a prime position to steal a game and, perhaps, start righting the ship.

Until the final drive when it all fell apart. Rather than continue doing what had gotten them to that point – being aggressive and attacking – Tarver dialed back his defense. Too many times on that final drive we saw him sending just three or four-man rushes against Rivers. Without that pressure up front, it’s no wonder that Branden Oliver gashed the Raiders for runs of 10 and 12 yards at will. Oliver capped the drive with a one-yard touchdown plunge that put San Diego ahead to stay and sent Oakland to it’s fifth consecutive defeat in 2014 – and 11 in a row overall.

Tarver took the teeth out of the defense on that final drive and went away from what had made them successful to that point in the game. He was calling plays as if he was afraid to lose the game, rather than calling plays to win the game – a hallmark of the Allen tenure. Simply put, on that final drive, Jason Tarver did not put his players, or his team, in a position to win. And it wound up costing Oakland a game they should have had.

Interim HC Tony Sparano – if he plans on convincing Mark Davis to drop the interim tag – needs to win some ballgames. To do that, he needs coaches and players who aren’t afraid to lose, who aren’t content to play it safe. Sparano has nothing to lose at this point. Except more games, which he will if he allows Tarver to continue running the defense.

The Raiders made some serious strides against San Diego. We saw flashes of the team they can be. The team we hope they will be. But to turn that corner once and for all, they need to cut loose the anchors dragging them to the bottom. Jason Tarver, like his former boss Dennis Allen, needs to be shown the door sooner rather than later.

Kevin Saito is a fiction writer, sports junkie, history nerd and NFL contributor to www.RantSports.com Follow him on Twitter, Facebook, or on Google