CINCINNATI -- The Bengals were one of the hottest teams in the league for about a month.

Then it all fell apart. Now they're all but mathematically eliminated from the postseason, and when that happens, they will extend the NFL's current longest active postseason victory drought to a 28th year.

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During the 2015 season, the Bengals were just minutes away from their first playoff win since 1990. Now they seem to be moving backward.

How did a team that routinely went to the playoffs get to this point? A series of bad decisions made over three seasons put the franchise back several years.

Here are some of the reasons the Bengals don't appear to be in a position to compete for a Super Bowl anytime soon:

The 2015 draft

Teams that rely heavily on the "draft and develop" method can't afford to make major mistakes with their draft classes. The Bengals missed badly in 2015.

They selected two tackles in the first two rounds, which wasn't a bad idea considering Andrew Whitworth would turn 34 that year. In an ideal world, first-round pick Cedric Ogbuehi could take over for Whitworth and second-round pick Jake Fisher could be Andre Smith's successor.

The Bengals either badly misjudged the talents of their picks, failed to develop them, or both. Paul Alexander, the offensive line coach tasked with bringing them along, left for the Cowboys after 23 years in Cincinnati and was fired after only seven games there.

The Bengals took Cedric Ogbuehi in the first round of the 2015 draft, a regrettable moment in a forgettable draft. Jonathan Daniel/Getty Images

Meanwhile, the Bengals' opinion of Ogbuehi has plummeted.

He has been a healthy scratch for most of this season, and when left tackle Cordy Glenn got hurt, the Bengals didn't even trust him as a replacement. They re-signed Smith off the street for a third stint instead.

Fisher has fared only a little better, struggling at right tackle in 2017 and failing to win the starting job over Bobby Hart. Any chance to see him at left tackle this season was snuffed out after he injured his back and went on IR.

Whiffing on a first-round pick can set a franchise back by itself, and the Bengals essentially whiffed on the entire draft. Only tight ends Tyler Kroft and C.J. Uzomah remain on the team, and while both are talented, neither has shown he is a No. 1 tight end yet.

That's one position among many the Bengals might have to address considering Tyler Eifert has been unable to stay on the field.

Letting Whitworth walk in free agency

The Bengals had their franchise left tackle, and they let him go without a suitable replacement.

The front office didn't want to give the 35-year-old Whitworth anything longer than a one-year deal, despite knowing what they didn't have in Ogbuehi. Ogbuehi struggled at both left tackle and right tackle, and it was already clear he wasn't the answer on either side.

The Bengals should've been begging Whitworth to stay after seeing Ogbuehi give up two sacks at left tackle to the Texans, especially considering they knew Pro Bowl guard Kevin Zeitler was leaving. Instead, they let Whitworth sign with the Rams, and he earned a Pro Bowl berth last season.

The Bengals essentially hoped for the best with Ogbuehi before they finally had to admit defeat and trade for Glenn. They addressed the vacant center position by drafting Billy Price in the first round, but they didn't do much on the right side of the line, settling for Hart and Alex Redmond at guard.

If the Bengals had kept Whitworth, they might have been able to focus their efforts on finding a right tackle this offseason. Instead, their best option was Hart, who leads the team with 11 penalties (two declined). Redmond is third on the team with seven penalties. Because the problem hasn't gotten better, this is another position the Bengals are going to have to address this year.

Promoting Zampese to offensive coordinator

There probably was a reason former Bengals offensive coordinator Ken Zampese spent 13 seasons as the Bengals' quarterbacks coach. He got passed over twice for the OC position, by Jay Gruden and Hue Jackson. When Jackson took the job as Cleveland's head coach in 2016, the Bengals didn't even appear to search for a new coach but instead settled on Zampese, announcing him as the new coordinator two days later.

The Bengals learned quickly that Zampese made a better assistant than coordinator. 2016 was a forgettable year, and 2017 was even worse. The Bengals opened with two home games, became the first team since 1939 to fail to score a touchdown at home through their first two games, and fired Zampese immediately.

The poor decision-making of Marvin Lewis has contributed mightily to the decline of the Bengals. AP Photo/John Minchillo

Although interim offensive coordinator Bill Lazor appeared to give them a boost, the bulk of the offense had been installed with Zampese at the helm. The Bengals had to work within the confines of what was already there and finished last in total offense.

The Bengals again declined to do a search, promoting Lazor to the job for 2018. For a while, it looked like the Bengals' offense had the ability to be competitive. Inconsistency and injuries eventually brought it down.

It became quite clear how wide the offensive gap is between the Bengals and teams such as the Chiefs and Saints, who blew them out of the water. It's hard to imagine they can close that gap without significant changes.

Re-signing Burfict

The Bengals rewarded linebacker Vontaze Burfict on Sept. 7, 2017, with a three-year, $32 million contract extension that included $11 million in guaranteed money. Burfict rewarded the Bengals by getting suspended the first four games of the 2018 season for a performance-enhancing drugs violation.

The Bengals stubbornly stood by Burfict instead of drafting a potential replacement despite his history of suspensions and injuries. Burfict has played in only six games this season, and when he has been on the field, he has looked like a shell of the player he once was.

Bengals coach Marvin Lewis declined to discuss Burfict after he performed poorly against the Chiefs, commenting that the topic wasn't even relevant. Burfict has gone from one of the toughest linebackers on the field to one who isn't even taken seriously anymore.

“He just quits on plays all the time,” said one NFL player whose team played the Bengals this year.

If Burfict is on the decline, then the Bengals are in trouble. Their free-agent acquisitions at middle linebacker haven't panned out, and their current roster is made up of players better suited as backups than starters. Third-round pick Malik Jefferson can't even get on the field.

While the Bengals structured Burfict's contract in a way that makes for a relatively painless exit, they have no other options on the team to replace him. Finding a successor in the draft won't be easy with all the holes they now have to fill, and it's something that should've been considered years ago.

Extending Lewis

The Bengals felt that sticking with Lewis after two mediocre seasons was better than completely blowing up the coaching staff, even though the end of last season would've been the perfect time to clean house.

Lewis' contract was expiring along with his assistants, and the Bengals could've had a new coach come in with his own staff. Instead, they extended Lewis for two years, giving at least some of his assistants two-year contracts as well.

Things seemed promising when the Bengals hired several respected assistants, including Teryl Austin as coordinator, but it fell apart midway through the season, ending with Austin's ousting as the defense posted historically bad numbers.

The team is now in a free fall, and the Bengals might still have to make the shake-up they passed on last year. If that's the case, then all they accomplished this season was angering a fan base that has chosen to stop going to the games.

Even if the Bengals choose to move on from Lewis and start over, all of their key players will be another year older. If they don't move on, they'll certainly lose the remaining fans they have.

The Bengals have a lot of promising young talent, but their most important players, and the players they have the most money invested in -- A.J. Green, Andy Dalton, Carlos Dunlap and Geno Atkins -- will all be over 30 next season. The Bengals' window hasn't closed yet, but it certainly could close quickly if they don't make changes. With the way the past three seasons have gone, it's clear the old way is no longer working.