In Romer’s analysis, he used statistics from NFL games during the 1998, 1999 and 2000 seasons. Romer assigned a value to first-and-10 plays on each yard line of the football field (length – 100 yards). Romer concluded that it was not a representative sample since teams rarely go for it on 4th down. To assess probability, Romer used third down statistics instead. Also, Romer used first quarter statistics because the score and the time left do not generally influence decisions early in the game.
Romer concluded through his study that a team facing a fourth-and-goal situation (meaning that the team is within at least 10 yards of the goal line) within five yards of the end zone is better off trying for a touchdown (on average). At midfield, there exists an argument on whether to go for it on any 4th down that is within five yards of the 1st down. Romer also felt that a team on its on 10 yard line (90 yards away from the end zone) is better off going for it if within at least three yards of the first down. 1,575 4th downs were sampled and teams went for it only seven times when it was better off kicking. Teams kicked 992 times out of 1,100 fourth downs when it was better to go for it. Ten percent of the 1,100 fourth downs resulted in a team going for it on 4th down.
The following data compares 4th down results from the 2001 and 2002 NFL Seasons:
2001 NFL Season
Courtesy of NFL.com
203 4th down completions (average of 6.5 completions per team – 31 teams)
468 4th down attempts (average of 15.1 attempts per team – 31 teams)
43.4 4th down percentage
There were 468 fourth down attempts during the 2001 NFL Season consisting of sixteen games for each of the 31 teams. Out of these 468 attempts, 203 were completed. This resulted in 43.4 percent of completions over attempts. The league had an average of 15.1 4th down attempts per team with the most being 25 and the least being 4. This average of 15.1 attempts shows that there is almost one 4th down attempt a game. Only three teams attempted to go for it less than 10 times. The league also had an average of 6.5 4th down completions per team with the most being 12 and the least being 2. Only five teams had more than 10 completions. San Diego had the best 4th percentage with 75 percent completing 3 out of 4 4th down attempts. Tennessee had the worst 4th percentage with 13.3 percent completing 2 out of 15 4th down attempts. Of the teams that went to the playoffs that year (New York (A), Oakland, Baltimore, Miami, New England, Pittsburgh, Tampa Bay, Philadelphia, San Francisco, Green Bay, Chicago and St. Louis) there was a 53.6 (89 completions/166 attempts) 4th down percentage. This shows that during this season, teams that went to the playoffs converted on 4th down at least half the time.
2002 NFL Season
Courtesy of NFL.com
252 4th down completions (average of 7.9 completions per team – 32 teams)
497 4th down attempts (average of 15.5 attempts per team – 32 teams)
50.7 4th down percentage
There were 497 fourth down attempts during the 2002 NFL Season consisting of sixteen games for each of the 32 teams. Out of these 497 attempts, 252 were completed. This resulted in 50.7 percent of completions over attempts improving from the previous year’s 43.4 percent. The league had an average of 15.5 4th down attempts per team with the most being 30 and the least being 9. This average of 15.1 attempts shows that there is almost one 4th down attempt a game. Only one team attempted to go for it less than 10 times. The league also had an average of 7.9 4th down completions per team with the most being 18 and the least being 3. Only seven teams had more than 10 completions. Cleveland had the best 4th percentage with 80 percent completing 8 out of 10 4th down attempts. Seattle had the worst 4th percentage with 28.6 percent completing 6 out of 21 4th down attempts. The addition of Houston into the NFL did not really matter to the better percentage from the previous year. Houston completed 5 of 14 4th down attempts for 35.7 percent. Of the teams that went to the playoffs that year (New York (A), Oakland, New York (N), Tennessee, Atlanta, Pittsburgh, Tampa Bay, Philadelphia, San Francisco, Green Bay, Indianapolis and Cleveland) there was a 58.2 (95 completions/163 attempts) 4th down percentage. This shows that during this season, teams that went to the playoffs converted on 4th down at least half the time.
Conclusion
Depending on the situation, teams should think more considerably on going for it
on 4th down. Although percentages of 4th down conversions have generally increased over the years, teams should consider going for it on short-yardage situations that are in field-goal range. Teams go for it on 4th down an average of 15 times. This should increase with better decision making instead heavy reliance on being conservative. Teams further from the end zone should still consider punting away the ball unless the distance for first down is within three yards. Even though many coaches of the NFL disagree with what David Romer has stated, those who have read his work have re-considered their approach on 4th down plays.
Appendix
Appendix 1: What is football? (courtesy of NFL.com)
History of Football
Fans' knowledge of football varies greatly. For the advanced fan, stick to NFL.com stats and standings. If you are new to the sport and would like to learn more, here are a few basics.
• Football evolved from the sports of soccer and rugby. The first football game between McGill University and Harvard took the appearance of a rugby game.
• The National Football League was born in 1920 when the official League documents were signed in a Hupmobile showroom in Canton, Ohio.
• In 1960, the American Football League (AFL) was born.
• In 1966, the AFL and NFL signed an agreement for the two leagues to merge and begin play as one league for the 1970 season.
• In 1967, the first AFL-NFL World Championship Game was played in Los Angeles. In 1969, the game commonly was referred to as the Super Bowl.
Essentials
• Football is a game of territory and strategy.
• 22 players are on the field at one time — 11 per team.
• An NFL game is made up of four 15-minute quarters, plus a 15-minute sudden-death overtime if the score is tied after regulation time.
• A 12-minute halftime falls between the second and third quarters.
• Each team is entitled to three time outs per half.
The Three "Teams" Within a Football Team
• Offense — controls the movement of the ball and attempts to score touchdowns (worth 6 points) by passing or running.
• Defense — attempts to stop the offense from scoring by tackling runners, deflecting passes, intercepting passes, or causing fumbles.
• Special Teams — a group of specialists who take the field during kicking situations: punts, field goals, extra points and kickoffs.
The Offense
• The offense attempts to score by passing or running the ball.
Positions
• Quarterback — leader of the team, high profile, executes most plays.
• Center — lines up over the football, in the center of the offensive line; snaps the ball to the quarterback to begin each play.
• Guards — each offensive team has two guards who line up on either side of the center.
• Tackles — each offensive team has two tackles who line up outside the guards.
• Tight end — lines up just outside the tackle (close or tight).
• Wide Receivers — line up 10-15 yards wide of the offensive line; receive passes thrown by the quarterback.
• Running Backs — line up behind the quarterback in the backfield; run with the ball, block, and receive passes from the quarterback.
The Defense
• The defense attempts to prevent scoring opportunities by tackling offensive players short of a first down or causing the offense to lose control of the ball (called turnovers).
The Positions
• Defensive Tackle — lines up on the defensive line; responsible for stopping the offensive charge; either one or two defensive tackles play depending on defensive formation.
• Defensive Ends — line up on the defensive line; responsible for containing the outside running game and for rushing the quarterback; a successful rush of the quarterback results in a sack; two defensive ends play at all times (see definitions).
• Linebackers — line up 2-3 yards in back of the tackles and ends; responsible for stopping the run and also for covering receivers on passing plays; occasionally rush the quarterback (referred to as a blitz).
• Cornerbacks — line up opposite wide receivers; responsible for covering receivers and providing support in stopping the running game; typically two cornerbacks play depending on the defensive and offensive formations.
• Safeties — line up 8-10 yards from the line of scrimmage; responsible for providing support in pass coverage (essentially the safety net against a long gain of yardage by the offense); typically two safeties play depending on the defensive and offensive formations.
The Special Teams
• Special Teams are responsible for kicking a ball or returning a kicked ball from the other team, and are frequently labeled kicking teams, or receiving.
• Kickoffs — start the game; start the second half; start play after team scores.
• Field-Goal Attempt — an effort by the offensive special team to score 3 points by kicking the ball between the uprights.
• Punt — an exchange of possession in which the offensive team tries to pin the ball in the defensive team's end of the field.
• Kick Returns — after the kicking team attempts to catch it and advance as far as possible toward the opposite end zone.
DOWNS
Fans' knowledge of football varies greatly. For the advanced fan, stick to NFL.com stats and standings. If you are new to the sport and would like to learn more, here are a few basics.
• Downs are a series of offensive plays.
• The offense has four downs to move the ball 10 yards.
• Upon moving the ball 10 yards, the offensive team receives another set of downs.
• First Down — first try (first and 10 yards to go).
• Second Down — second try.
• Third Down — third try.
• Fourth Down — last and final try; with options (see below).
• Go For It — try to get the yardage necessary to attain a first down or a touchdown.
• Kick a Field Goal — attempt to score three points by kicking the ball between the uprights.
• Punt — kick the ball to the other team in hopes of keeping it as far away from your goal line as possible.
2nd Quarter: X's and O's
SCORING
Touchdown: six points
• Running the ball or completing a pass to a player who carries the ball into the opponent's end zone.
Extra Point: one or two points
• An effort to score points after a touchdown by either:
• A. Kicking the ball through the uprights (one point).
• B. Running or completing a pass to a player who carries the ball into the end zone from two yards away (two points due to difficulty).
• In either case, the offensive team gets only one opportunity to execute a point after a touchdown.
Field Goal: three points
• Field goals usually are attempted in 4th-down situations (last attempt or try in a series of downs).
• Special teams will attempt a field goal if it feels the kicker is close enough to the end zone to kick the ball through the uprights.
• A field-goal attempt must clear the crossbar and go between the uprights.
Safety: two points
• Safeties are the rarest of all the scoring opportunities. The defensive team is credited with two points if it tackles an offensive player in his own end zone.
• Don't confuse the term "safety" with the defensive position.
References
- Pro-Football-Reference.com
-
Garber, Greg. Fourth-down analysis met with skepticism (Article courtesy of ESPN.com)
- ESPN.com
- NFL.com
-
Romer, David. It’s Fourth Down and What Does The Bellman Equation Say? (NBER Working Paper Series)
