Josh Allen could easily have been typecast after two full seasons as one of many quarterbacks drafted in the first round who just don't work out.

Tight end Dawson Knox could have been similarly written off without a second thought.

Same applies to Buffalo Bills teammates such as running back Devin Singletary, cornerbacks Taron Johnson and Levi Wallace and defensive tackle Ed Oliver.

But patience and diligent player development have helped set the Bills apart from so many other NFL teams, leading to a roster that's as balanced as it is deep.

Allen is the most noteworthy. His first season was rocky. His second was a little better, but uneven. And he was shaky at best after the Bills grabbed a lead at Houston in the playoffs, playing poorly down the stretch in an overtime loss.

After two seasons, he had completed just 56.3% of his passes — lousy by today's standards, but not as lousy as his average of 6.6 yards per attempt. He had thrown 31 touchdown passes against 21 interceptions, fumbled 22 times and absorbed 66 sacks in just 28 games.

Almost every major quarterback bust of the past decade had similar or better numbers after two seasons than Allen. The list includes Robert Griffin III, Sam Bradford, Blaine Gabbert, Blake Bortles, E.J. Manuel and Sam Darnold.

Even the biggest bust of all, the drug-addicted Johnny Manziel, had higher completion and lower interception percentages than Allen.

But in the ensuing offseason, instead of using their first-round draft pick on another quarterback, which many other teams would have done under the same circumstances, the Bills traded it to the Minnesota Vikings for wide receiver Stefon Diggs.

Their decision to help Allen get better rather than initiate contact with a divorce lawyer paid off more than maybe even anyone inside their building could have imagined.

Allen was runner-up in the league MVP voting, Diggs led the league in receptions and yards and the Bills' new offensive juggernaut went to the AFC Championship Game. All of that led to Allen being rewarded two months ago with a monster contract extension worth up to $258 million.

Although the Bills had their franchise quarterback and some excellent receivers, they still didn't have a tight end, according to experts.

And the experts were right. Looking in from the outside, there was no reason to believe Knox was going to go from someone who had 14 drops and a 55% catch percentage while totaling just 52 catches in 27 games to a dependable target who this season already has 15 catches through four games, with just one drop and a 75% catch percentage,

But as with many players who may not be ready to play at the required level right away, the Bills have been patient with bringing them along with an army of nurturing assistant coaches and a firm understanding of how the contstraints of a pandemic can serve to stunt a player's development.

For instance, the Bills correctly surmised that the dip in Oliver's production from his rookie year of 2018 to his sophomore season of 2020 had to do with the way opponents attacked him with double teams without the presence of Star Lotulelei, who opted out of last season because of COVID-19 concerns.

They believed Oliver would be just fine in 2021 with Lotulelei's return and the addition of edge rushers Greg Rousseau, Boogie Basham and Efe Obada. Again, sensible instincts that are paying off.

Same thing at cornerback.

Ever since Wallace stuck with them as an undrafted free agent and cracked their starting lineup as a rookie in 2018, he and the Bills have been hearing how an upgrade is needed at that position opposite proven All-Pro Tre'Davious White.

And although the Bills did draft Dane Jackson in the seventh round and bring veteran Josh Norman in last year, they recognized Wallace was still their best option and stuck with him.

In the offseason, they resisted outside pleas for them to add a big-name free agent or use a premium pick on a rookie.

Turns out they were right again.

They often put their money where their mouth is too, like they did with Allen and most recently with nickel corner Johnson, who on Saturday signed a three-year contract extension worth $24 million.

Johnson's career was not exactly trending upward after his first two seasons, which were plagued by injuries and bouts of ineffectiveness as he earnestly reshaped his body to withstand the rigors of the NFL. Since the start of last season, he has been such a different player that the Bills saw fit to lock him in now.

After the 2020 season, the Bills also could have moved on from Singletary to hardly anyone's surprise. After all, rookie Zack Moss had surpassed him by the end of the regular season before getting injured in the playoffs, forcing the Bills to turn back to Singletary, whose yards-per-carry dropped from 5.1 in 2019 to 4.4 in 2020.

But after an intense offseason training program designed to make him stronger like Johnson, he has responded by being Buffalo's leading rusher through four games, averaging 5.3 yards on 49 attempts.

The Bills' willingness to work with players and not give up on them as quickly as others in a league that's arguably defined by impatience has made a difference in a culture that's been evident since Day 1 of coach Sean McDermott's arrival in 2017.

It's a winning dynamic, to be sure.

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