Could the arrival of wide receiver Jeremy Maclin propel the Kansas City Chiefs past the Broncos and Chargers? (Ed Zurga/Associated Press)
Kansas City Chiefs (2014 Record: 9-7)

OUTLOOK: The Chiefs spent big money to re-sign pass rusher Justin Houston and add free agent WR Jeremy Maclin. They probably should have been a playoff team last season but ultimately were unable to overcome losses to the Titans and Raiders. The Chiefs cannot make such missteps this season if they’re to overtake the Broncos and Chargers in the AFC West.

IMPACT ADDITION: Maclin’s arrival in free agency is supposed to be the cure for the ills of a Chiefs wide receiver corps that didn’t have a single TD catch last season. But is Maclin a legitimate No. 1 wideout? He seemed to qualify as that in Philadelphia last season, when he had 85 catches for 1,318 yards and 10 touchdowns. But that was his first career 1,000-yard season and he previously had been a clear No. 2 behind DeSean Jackson with the Eagles.

FANCY STAT: 1.56

Average points allowed per drive by the defense, the sixth best in the NFL.

Denver Broncos (12-4)

OUTLOOK: Does QB Peyton Manning have one more season of greatness in him? It would be tough, as always, to doubt him. How about a run at a second career Super Bowl title? That could be trickier. Front-office chief John Elway cleaned house after last season’s playoff one-and-done, and now Manning must adjust to a new coach, in Gary Kubiak, and a new offensive system.

IMPACT ADDITION: Manning took a $4 million pay cut during the offseason, and the Broncos later signed Pro Bowl G Evan Mathis to a one-year deal worth as much as $4 million. Coincidence? If Manning’s reduction in income did pay for Mathis’s contract, it could be money well spent for him. The Broncos were vulnerable to an up-the-middle pass rush last season. Manning is at his best when he doesn’t have to move in the pocket.

FANCY STAT: 47.8

Opposing QB rating on throws with Chris Harris Jr. in coverage, the second lowest in the NFL.

San Diego Chargers (9-7)

OUTLOOK: The Chargers, like the Rams and Raiders, face the uncertainty of a possible move to Los Angeles following the season. In the Chargers’ case, at least the talk that QB Philip Rivers wouldn’t relocate with them is over, now that Rivers has a new contract in place. He was an MVP candidate for part of last season before falling off the pace. He probably will need to have a special season for the Chargers to be in the mix of top AFC contenders.

IMPACT ADDITION: Melvin Gordon was the second running back drafted, taken five spots after the Rams chose Todd Gurley. If Gordon can establish himself as an immediate threat in the running game, the biggest beneficiary might be Rivers.

FANCY STAT: 2.8

Percentage of plays RB Danny Woodhead was stopped behind the line of scrimmage, the lowest among rushers with at least 100 attempts.

Oakland Raiders (3-13)

OUTLOOK: Jack Del Rio probably is the right coach for this situation, and there is reason to believe the Raiders will improve. They have won four games or fewer in three consecutive seasons and haven’t reached the playoffs since the 2002 campaign. Derek Carr quietly had a productive rookie season at QB, throwing for 3,270 yards and 21 TDs with 12 interceptions. He should be better as a second-year pro, and the arrival of rookie WR Amari Cooper should provide a major boost.

IMPACT ADDITION: The Raiders already look good for taking Cooper over Kevin White as the first wide receiver off the board in the draft. White is sidelined by a shin injury that required surgery. Cooper wasn’t as eye-catching as White was during the pre-draft process. But he is a smooth, efficient receiver who should make a seamless transition to the pro game.

FANCY STAT: 4.5

Yards per offensive play, the worst in the NFL.