At times, Chan Gailey showed he was willing to adjust. When he became Buffalo Bills head coach three seasons ago, he switched from a 4-3 defensive system to a 3-4. This year, he flipped his defense back. After determining Trent Edwards was the clear quarterback choice, Gailey pulled the plug two games into 2010 and elevated Ryan Fitzpatrick. Gailey obviously can adapt when he wants to. Yet his refusal to change, his stubbornness on certain players and strategies, will be what doomed him in Buffalo.

The Bills' front office has made some puzzling moves over the years, but few would be more unexpected than Gailey sticking around beyond this afternoon's game against the New York Jets in Ralph Wilson Stadium.

Today will conclude the Bills' 13th straight season without the playoffs. In that span, the Jets have dismantled and rebuilt themselves a few times, qualifying for the postseason with three different head coaches and reaching the AFC title game twice in four years under Rex Ryan, whose future is cloudy.

Imagine, then, what standard the Bills would apply to justify keeping Gailey, whose record is 15-32 and whose program has shown no obvious signs of progress despite an improved roster each season.

Even with those splashy offseason moves, drafting two promising starters at critical positions and a breakout season from C.J. Spiller, the Bills must win today to equal last year's record.

Bills General Manager Buddy Nix has preached the need for continuity. Nix wants to end the cycle of hiring a new head coach every three or four years. But continuity can be synonymous with treading water.

Gailey's biggest flaws became indisputable in 2012. He was inflexible in the way he used his players and executed strategies.

He has refused to let go of Ryan Fitzpatrick as if the quarterback were a life preserver and found excuses not to ride Spiller, who looks every bit the part of an NFL superstar when the coach hasn't taken him off the field.

Gailey also erred in giving old pal Dave Wannstedt full control of the defense, so much so that when reporters would ask Gailey about the intricate workings of Wannstedt's systems and philosophies, Gailey would shrug.

Whether truly resigned to what Wannstedt was up to or just unwilling to answer probing questions, Gailey had ceded authority over a unit that started off historically bad, then improved for a bit, yet still could set Buffalo's record for points allowed.

Buffalo has yielded 426 points, already third-worst in club history. That's one more point than Gailey's 2010 team allowed and eight fewer than last year's team, giving Gailey three of Buffalo's four all-time worst defenses.

If the Jets score 29 points today, then the Bills will surpass their record from 1984. Those Bills went 2-14 under Kay Stephenson.

Gailey can't be forgiven for Buffalo's defensive ineptitude. It was Gailey's decision to hire George Edwards and switch from Dick Jauron's Tampa 2-style defense to a 3-4.

It was Gailey's decision to fire Edwards after last season, promote Wannstedt from linebackers coach and morph back into a 4-3.

Edwards was one of Gailey's many assistants out of their depth. Gailey filled out his coaching staff with acquaintances from when he coached at Georgia Tech and was Kansas City Chiefs offensive coordinator.

Of the seven position coaches and three coordinators on Gailey's original Bills staff, seven had two or fewer years of NFL experience in their given roles. Four had zero seasons of NFL experience in those roles.

Gailey's approach to constructing a defensive staff was regrettable, but he at least was expected to make wonderful things happen on the other side of scrimmage.

Gailey was hired because of his offensive acumen and his reputation for being a master at maximizing a quarterback's talents.

The entire organization has been stunted by Fitzpatrick's erratic performances and an inability to groom a quarterback of the future. Nix deserves significant blame for that. The GM has taken only one quarterback in his three drafts – Levi Brown from Troy University in the 2010 seventh round.

But Gailey certainly had influence over how the Bills handled the position moving forward.

As Bills head coach, Gailey has worked with eight quarterbacks. None of them have moved the team – or, aside from Fitzpatrick, their careers – forward.

Gailey identified Trent Edwards as the clear-cut choice to be the starter in 2010, giving Edwards all of the first-team reps throughout minicamp, voluntary workouts and training camp. Edwards started all four preseason exhibitions, then was dumped after two regular-season games.

From that moment on, perhaps because Gailey couldn't bring himself to admit he was wrong twice in managing the one position he was hired to reinvigorate, Gailey inexplicably became devoted to Fitzpatrick's mediocrity.

Gailey risked his career first with a collection of unproven assistants, then with a career backup quarterback with a losing record and no playoff experience.

Buffalo's other quarterbacks were marginalized and didn't develop.

Brian Brohm became a United Football League backup. Brown has been a Canadian Football League backup. Brad Smith was declared the third-string quarterback early but was playing receiver full-time by training camp. Vince Young is unemployed. Tyler Thigpen should be. Tarvaris Jackson has been inactive all season.

The Bills, meanwhile, have been beaten convincingly by the past three rookie quarterbacks they've faced.

Beyond a lack of quarterback cultivation, Gailey wasn't too creative or intuitive with his game plans.

Gailey was able to turn overlooked players such as castoff tight end Scott Chandler and undrafted receivers Donald Jones and David Nelson into serviceable players. Gailey and offensive line coach Joe D'Alessandris also admirably managed a unit that hasn't looked overly imposing on paper.

But limiting sacks with a quick-read passing game and squeezing production out of the bottom of the roster have been diminished by conservative decisions like punting from around an opponent's 35-yard line three times this year and refusing to give Spiller more touches in a season that ranked among the best of the past 80 years in yards per carry.

As great as Spiller has been, Gailey has preferred to base his offense on Fitzpatrick.

Gailey's usage of Spiller is reminiscent of what former Bills coach John Rauch did with O.J. Simpson in 1969 and 1970. The Heisman Trophy winner and first overall pick averaged 14.3 carries a game in an era when ground attacks ruled.

Simpson didn't become a workhorse runner until Lou Saban became head coach. Simpson led the NFL in carries three times and yards four times.

Perhaps the most telling snapshot of how little the Bills have evolved throughout Gailey's tenure can be found in the scoring.

The Bills were pathetic through the first couple months of 2010, Gailey's first season. They were so poor that Las Vegas Sports Consultants, the prominent oddsmaking firm for legal sports books, forecasted the Bills would be a 10.5-point favorite to beat the best UFL team on a neutral field.

Opponents in 2010 outscored the Bills, 236-128, in the first half, an average margin of minus-6.8 points. The 2012 Bills have been outscored, 195-189, in the first half, a respectable margin of minus-1.1 points.

But in the second half this year, the Bills have been annihilated, 231-134, a differential of minus-6.5 points.

Over the course of a game and over the course of years, Gailey has been unable to adjust.