The success of a college football team hinges on its starting quarterback more than ever, but for the second consecutive year the SEC is getting subpar play at the game’s most important position.

The top six QBs in the conference measured by passer efficiency rating (among those who qualify nationally) play on teams that have lost a combined 18 times, and none will be anywhere near the SEC Championship Game — let alone the College Football Playoff.

Brandon Allen of Arkansas (10th in the country), Chad Kelly of Ole Miss (20th), Dak Prescott of Mississippi State (29th), Greyson Lambert of Georgia (31st), Brandon Harris of LSU (37th) and Kyle Allen of Texas A&M (42nd) have been all over the place as a group.

Brandon Allen dropped four of his first six starts. Kelly beat Alabama but lost to Memphis. Prescott faced three ranked foes and didn’t defeat any of them. Lambert was benched. Harris hasn’t been able to pick up the slack now that Leonard Fournette looks human. Kyle Allen was also benched.

The two passers on a collision course for the conference title game, Florida’s Treon Harris and Alabama’s Jake Coker, rank 58th and 62nd, respectively, in the nation in efficiency.

Harris lost the battle for the starting job to Will Grier but took over once Grier was suspended by the NCAA after testing positive for PEDs. More of a scrambler than a thrower, Harris has completed only 55.6 percent of his passes and fired just 6 touchdown passes in eight games.

Coker seems like the weak link on a ‘Bama team peaking at the right time, as the running game is terrifying, the pass catchers are explosive and all three levels of the defense are dripping with draft picks. Despite the talent around him, Coker has an uninspiring 12-to-8 TD-to-INT ratio and is a negative play waiting to happen when pressured.

Why it matters

From 2008-13, the final six years of the BCS era, the quarterback for the national champion was ranked 10th in the FBS on average in efficiency — two finished No. 1, and none was lower than 28th.

Last season, Ohio State’s J.T. Barrett was second despite missing the last three games with injury. Cardale Jones didn’t have enough attempts to qualify, but his 160.2 rating would have been seventh.

In 2013, the SEC had five of the 12 most efficient signal callers in the nation: Texas A&M’s Johnny Manziel, LSU’s Zach Mettenberger, Alabama’s AJ McCarron, South Carolina’s Connor Shaw and Georgia’s Aaron Murray.

“I am not sure if it really is that bad to be honest,” said former South Carolina quarterback Stephen Garcia, who is now a contributor for Saturday Down South. “From top to bottom, I think it has actually improved from a year ago. We will have several 3,000-yard passers.

“Yes, the turnovers have been an issue, but defenses are getting much faster and used to this new spread-type offense. We are also seeing much more gunslinger quarterbacks that feel they have the arm to make sticky throws.”

While Garcia’s analysis is more about the eye test, which is hard to dispute for an ex-player of his credentials, the raw numbers don’t necessarily agree with him.

A year ago, Blake Sims of Alabama was the seventh-rated QB in the country. Hutson Mason of Georgia was 10th. Prescott was 14th as a junior — 15 spots higher than where he sits now as a senior. Nick Marshall of Auburn was 15th.

“One thing we don’t have is this: We don’t have a big-name type guy,” Garcia said. “We have Prescott, who probably was the biggest name entering into the season. I think going into next year we will have several guys with big names — Kelly, (Tennessee’s Joshua) Dobbs and Grier to name a few.”

Big players win big games. The quarterbacks who participated in last year’s Final Four? Jones, Sims, Jameis Winston and Marcus Mariota.

Searching for answers

Garcia’s alma mater has started three players under center in 2015, and the current starter, Perry Orth, is the 98th most efficient QB in the land for the 3-7 Gamecocks.

Auburn began the campaign ranked No. 6 in the AP poll, with new starter Jeremy Johnson generating some buzz for the Heisman Trophy during the preseason — he was supposed to be a better thrower than Marshall, and maybe just as good a runner. But his passer rating of 119.7 is only a tick higher than Orth’s 118.5, which has resulted in him getting pulled and the Tigers stumbling to 5-5.

At Kentucky, one former No. 1 recruit in the Bluegrass State is getting the hook in favor of another, as junior Patrick Towles and his conference-high 13 interceptions are out and freshman Drew Barker gets his first start Saturday.

It’s hard to pinpoint an exact reason QB play is down across the SEC, but Rachel Baribeau, the host of College Sports Nation on SiriusXM, has been exposed to every hypothesis out there.

“There are many theories, from the abbreviated time that coaches get to spend with these guys to falling in love with a big arm to getting married to a kid before the instinctual stuff catches up,” Baribeau said. “I have even heard some call what’s going on with Jeremy Johnson legitimate stage fright.”

Baribeau tweeted during last Saturday’s Alabama-Mississippi State game that Coker is coach Nick Saban’s “hamartia,” or fatal flaw, even with all those futures pros around him.

“He is not an ideal QB,” she said, “although Saban has praised his ability to be physical, tough and get key third downs in really heated spots in tight games.”

While Baribeau doesn’t give Harris much of a shot against the Crimson Tide in the conference title game, she praised Florida coach Jim McElwain’s ability to make lemonade en route to a division crown.

“Harris has had some bright moments,” she said, “especially in the LSU game, but that offense as a whole has also stunk up the joint.”

Regardless of who emerges from the Coker-Harris matchup next month, recent QB history suggests neither will ultimately deliver another national championship for the SEC.