ENGLEWOOD, Colo. -- As the Denver Broncos try to repair all that went wrong in a troubled 2017 season, one of the most difficult hurdles for them to clear will be their own recent history.

Because as they try to fix an offense that has largely failed them in back-to-back seasons, they must do it in the rather large shadow of a memory. As in four seasons ago, where the Broncos produced more points in a season than any offense in league history.

The 2013 Broncos were the only 600-point team in NFL history, totaling 606 in their 16 games, as Peyton Manning set league records with 5,447 yards passing and 55 touchdowns. The Broncos had two 1,200-yard receivers in Demaryius Thomas and Emmanuel Sanders to go with a 1,000-yard rusher in Knowshon Moreno.

To put all that in perspective, the Broncos have scored 622 points and have thrown 39 touchdown passes in the past two seasons combined. The makeover is on the way and these are what will be the biggest decisions:

Decide who they are: The time of gathering players to suit the whims of each new position coach is over. The Broncos have to decide what they want to be and gather players for that, especially in the offensive line and at quarterback -- just four of the nine offensive linemen on the roster to end the season are Broncos' draft picks. Talk to evaluators around the league and many say the Broncos spent much of the season trying to be something they were not on offense. Their continued attempts to play out of a three-wide receiver set, with the quarterback in the shotgun, was ineffective and many of their game-changing mistakes came out of that formation. In their first 12 games, including their eight-game losing streak, 31 of their 40 sacks allowed were out of the three-wide set and 14 of their 18 interceptions were thrown out of it. It cost offensive coordinator Mike McCoy his job in November as well as three other assistants on offense at season’s end. Also, the Broncos had five games in a 5-11 season when they ran the ball more than they threw it -- all five of their wins. GM John Elway noticed as well: “Offensive football is about getting the best players we can possibly get and putting them in the best situations to be successful. And we’ve got to do a better job of that. We didn’t do a great job at that this year. That is something we definitely have to get better at.’’

Find the Alpha: Look, everybody knows the Broncos are on the hunt for a quarterback who can walk it, talk it and throw it. But beyond the skill set, the Broncos need a set-the-tone guy. Because their locker room, by the admission of their own veteran players, has many younger players that didn't seem all that interested in grinding. The Broncos need somebody on offense -- they really hope it’s a quarterback -- who can pull the younger players along. Until it happens, the Broncos will continue to have several first- and second-year players thinking they’re doing enough, with plenty of veterans angry that those same young players haven’t done enough.

Define the rules: Again, losing often brings out the complaints. But overall, there was a sense among some of the team’s more experienced players that there wasn’t enough accountability across the board, especially on offense. And while every head coach deserves the opportunity to set his own tone, including Vance Joseph, player after player has said the type of critiques by Manning and the Monday morning review of mistakes former coach Gary Kubiak held in the team meeting room were missing. The Broncos have to find some sense of purpose where all of the players know what, exactly, gets them in the lineup and what removes them from the lineup -- no exceptions.

Close the deal: The Broncos scored 27 touchdowns on offense in 2017. Opposing offenses scored 39. There is the season in a nutshell. Red zone play is about matchups and your players winning them. The Broncos didn’t win enough up front or in the pass pattern. Their quarterbacks contributed to that, to be sure. But C.J. Anderson, Devontae Booker and Jamaal Charles had a combined two rushing touchdowns after Nov. 1, while Sanders didn’t have a touchdown catch after Week 2 as he missed practice and game time after a Week 6 ankle injury. The Broncos had no 100-yard receiving games after Nov. 12 and none from anybody other than Thomas and Sanders. And other than that duo, the Broncos had no other player catch more than six passes in any game.