Are Bills weighed down by dead money?

With two head coaches, two general managers, and three defensive coordinators since the 2012 season, the Buffalo Bills are no strangers to personnel and scheme changes.

With shifts in philosophy will come collateral damage to the salary cap. It's no surprise, then, that the Bills' dead money against their cap is the second-most in the NFL this season.

ESPN NFL Insider Kevin Seifert breaks down each team's dead-money situation in a recent piece, noting that the Bills' $22.7 million in dead money ranks second behind the Dallas Cowboys ($23.2 million).

"Dead money" is salary-cap charges for players who are no longer on the roster. When a player is released or traded, his yearly allocation of signing bonuses against the salary cap remains.

Most of the Bills' dead money comes from releasing quarterback Ryan Fitzpatrick ($7 million) and trading wide receiver Stevie Johnson ($10.225 million). Only quarterback Matt Schaub, who was traded by the Houston Texans earlier this offseason, counts more against his former team's cap.

Even though Fitzpatrick hasn't played for the Bills since 2012, his dead money charge ranks seventh in the NFL.

How much of a problem is dead money for the Bills? With $7.9 million in remaining cap space this season, it hasn't prevented them from doing business. It's doubtful that having less dead money would have increased the team's willingness to re-signing Jairus Byrd, for example.

However, the dead-money charges suggest that the Bills didn't make the wisest moves in extending either Fitzpatrick or Johnson.

After Fitzpatrick and the Bills began the 2011 season with a 4-2 record, with Fitzpatrick throwing 12 touchdowns in his first six games, the team gave him a six-year, $59 million extension with $24 million guaranteed. Fitzpatrick went 8-18 in the remainder of his career in Buffalo and was released after the 2012 season.

Following the 2012 season, Johnson received a five-year, $36.25 million extension. He enjoyed a productive 2012 season but ran into injury problems last season. Ultimately, the fit wasn't right for him in Doug Marrone's system, and Johnson was shipped out to make room for first-round pick Sammy Watkins.

Both cases serve as cautionary tales for more recent free-agent signings and contract extensions. Extending Aaron Williams for four seasons at $26 million, as one example, seems like a wise move now. But is Williams' level of play consistent with him being paid like top NFL safeties? That remains to be seen.