2004 NFL season

• February 24, 2004, Washington released Bruce Smith, the NFL's all-time sack leader, saving $6.5 million in salary cap space.[1]

Ron Blum returned to line judge, and Bill Vinovich was promoted to take his place as referee.

Midway through the season, Johnny Grier, the NFL's first African-American referee, suffered a leg injury that forced him to retire. He was permanently replaced by the back judge on his crew, Scott Green, who had previous experience as a referee in NFL Europe.

• Due to several incidents during the 2003 NFL season, officials are authorized to penalize excessive celebration. The 15-yard unsportsmanlike conduct penalty will be marked off from the spot at the end of the previous play or, after a score, on the ensuing kickoff. If the infraction is ruled flagrant by the officials, the player(s) are ejected.
• Officials are instructed to strictly enforce illegal contact, pass interference, and defensive holding.
• Timeouts can be called by head coaches.
• In addition to the numbers 80–89, wide receivers will now be allowed to use numbers 10–19.
• A punt or missed field goal that is untouched by the receiving team is immediately dead once it touches either the end zone or any member of the kicking team in the end zone. Previously, a punt or missed field goal that lands in the end zone before being controlled by the kicking team could be picked up by a member of the receiving team and immediately run the other way.
• Teams will be awarded a third instant replay challenge if their first two are successful. Previously, teams were only limited to two regardless of what occurred during the game.
• The one-bar facemask was officially outlawed. The few remaining players who still used the one-bar facemask at the time were allowed to continue to use the style until they left the league under a grandfather clause.

• Pat Tillman former safety for the Arizona Cardinals was killed during a friendly fire incident during the war in Afghanistan

• Reggie White former defensive end for the Green Bay Packers, Philadelphia Eagles, and Carolina Panthers unexpectedly died on December 26, 2004 just seven days after his 43rd birthday from complications of sleep apnea

Within each conference, the four division winners and the two wild card teams (the top two non-division winners with the best overall regular season records) qualified for the playoffs. The four division winners are seeded 1 through 4 based on their overall won-lost-tied record, and the wild card teams are seeded 5 and 6. The NFL does not use a fixed bracket playoff system, and there are no restrictions regarding teams from the same division matching up in any round. In the first round, dubbed the wild-card playoffs or wild-card weekend, the third-seeded division winner hosts the sixth seed wild card, and the fourth seed hosts the fifth. The 1 and 2 seeds from each conference then receive a bye in the first round. In the second round, the divisional playoffs, the number 1 seed hosts the worst surviving seed from the first round (seed 4, 5, or 6), while the number 2 seed will play the other team (seed 3, 4, or 5). The two surviving teams from each conference's divisional playoff games then meet in the respective AFC and NFC Conference Championship games, hosted by the higher seed. Although the Super Bowl, the fourth and final round of the playoffs, is played at a neutral site, the designated home team is based on an annual rotation by conference.

The Miami Dolphins were the first team to be eliminated from the playoff race, having reached a 1–9 record by week 11.[2]

* Indicates overtime victory

The following teams and players set all-time NFL records during the season:

The Colts led the NFL with 522 points scored. The Colts tallied more points in the first half of each of their games of the 2004 NFL season (277 points) than seven other NFL teams managed in the entire season.[4] Despite throwing for 49 touchdown passes, Peyton Manning attempted fewer than 500 passes for the first time in his NFL career.[5] The San Francisco 49ers record 420 consecutive scoring games that had started in Week 5 of the 1977 season ended in Week 2 of the season.

• Arizona Cardinals – Dennis Green replaced Dave McGinnis who was fired after the 2003 season
• Atlanta Falcons – Jim L. Mora replaced Wade Phillips who replaced Dan Reeves who was fired during the 2003 season
• Buffalo Bills – Mike Mularkey replaced Gregg Williams who was fired after the 2003 season
• Chicago Bears – Lovie Smith replaced Dick Jauron who was fired after the 2003 season
• Oakland Raiders – Norv Turner replaced Bill Callahan who was fired after the 2003 season
• New York Giants – Tom Coughlin replaced Jim Fassel who was fired after the 2003 season
• Washington Redskins – Joe Gibbs replaced Steve Spurrier who resigned after the 2003 season

• Carolina Panthers: Ericsson Stadium was renamed Bank of America Stadium after Bank of America acquired the naming rights.
• Minnesota Vikings: The AstroTurf at the Metrodome was replaced with a new FieldTurf field.
• Oakland Raiders: Network Associates Coliseum was renamed McAfee Coliseum to reflect naming right holder, Network Associates, changing its name to McAfee.
• San Francisco 49ers: Monster Cable acquired the naming rights to Candlestick Park, renaming it merely to "Monster Park" without any qualifier. This eventually results in confusion among fans who erroneously think the name instead refers to Monster.com or Monster Energy.[6]
• Seattle Seahawks: Seahawks Stadium was renamed Qwest Field after telecommunications carrier Qwest acquired the naming rights.

• The Atlanta Falcons switched the primary and alternate jerseys, making the red ones the primary and the black ones the alternate.
• The Baltimore Ravens added black third alternative uniforms.
• The Cincinnati Bengals introduced new uniforms, featuring black jerseys with orange tiger-striped sleeves, white jerseys with black tiger-striped sleeves, and orange third alternate uniforms. A new logo featuring an orange "B" with black tiger stripes was also unveiled.
• The Chicago Bears added orange third alternate uniforms.
• The Indianapolis Colts switched from blue face masks and white shoes to gray face masks and black shoes
• The Jacksonville Jaguars made modification to their white uniforms, changing the teal number with black and gold trim to black numbers with gold and teal trim. Also introduced were new black pants with the Jaguars logo on hip.
• The New York Giants added red third alternate uniforms.
• The San Diego Chargers returned to navy pants with their white jerseys.

• Football Outsiders 2004 Team Efficiency Ratings

• NFL Record and Fact Book (ISBN 1-932994-36-X)
• NFL History 2001– (Last accessed October 17, 2005)
• Total Football: The Official Encyclopedia of the National Football League (ISBN 0-06-270174-6)
• Celebration penalty among rules changes (Last accessed October 17, 2005)