"The only thing the prevent defense does is prevent…

The “prevent defense” is a football defense employed in the last seconds of a game (or a half); extra defensive backs are added to prevent the long touchdown throw. However, the prevent defense usually allows a lot of easy yards underneath the deep coverage. “The only thing the prevent defense does is prevent you from winning” is a frequent criticism of the prevent defense.

John Madden, a football head coach with the Oakland Raiders and an NFL color commentator/analyst from 1979 to 2008, is often credited with the famous “prevent defense” criticism, but it’s unlikely that he originated it. “The ‘prevent’ has long been a favorite of many coaches and announcers; only cynical viewers will notice that it usually prevents teams like the Skins from winning” was cited in print in 1969. “All that does is prevent you from winning” was cited in print in 1979.

Wikipedia: Prevent defense
Prevent defense is an American football defensive alignment that uses seven or more defensive backs or players in a defensive back role, the goal of which is to prevent the opposing offense from completing a long pass. This defense is frequently used in obvious passing situations, such as a third-and-very-long situation, or to prevent a long score on the last play of a half, or when the defense believes that the offense must pass (for example, if the offense is trailing late in a game). Otherwise the prevent is almost never used. The defense trades size for speed, and tries to ensure that no receiver can get behind the defense. A prevent defense backs up the coverage so far that it will often give up long yardage, but it makes scoring a touchdown in a single play very difficult.
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Disadvantages
The prevent defense is rarely used on consecutive downs, or with a significant amount of time remaining, since a team with time to move downfield would easily be able to gain plenty of intermediate yardage. John Madden once said, “All a prevent defense does is prevent you from winning.”

23 March 1969, Sunday Herald Trave3ler (Boston, MA), Magazine, pg. 8, col. 5:
“The Skins are going into their prevent defense to prevent the long bomb that could tie it up.”
(The “prevent” has long been a favorite of many coaches and announcers; only cynical viewers will notice that it usually prevents teams like the Skins from winning, by assuring the opposition of six straight short sideline passes that require about 40 seconds more than the feared bomb and produce the same touchdown. Commentators never remind people of this little drawback.)

8 November 1979, Trenton (NJ) Times, “Giants cut Hammond from their ‘family’ tree” by Mark Blaudschun, pg. C1, col. 1:
It began innocently enough on Sunday following the Giants’ frustrating 16-14 last-second loss to the Cowboys. A few players had some mild second guesses about the “prevent defense” used by coach Ray Perkins in the last three minutes, a defense that only prevented the Giants from winning their fifth game in succession.

7 December 1979, Trenton (NJ) Times, “Pro Football: Philadelphia prognostications” by Bus Saidt, pg. C2, col. 3:
AS SOON AS Dick Vermeil goes into his “prevent” defense, discussions will break out all over about the stupidity of the tactic and at least one grandstand coach will say, “all that does is prevent you from winning.”

Google News Archive
18 October 1982, Observer-Reporter (Washington, PA), “W&J: 35 Seconds Of Frustration” by Tom Rose, pg. C-6, col. 4:
“The only thing a prevent does is prevent you from winning.”
(Washington & Jefferson College coach John Luckhardt—ed.)

Google Books
30 December 1989, Waycross (GA) Journal-Herald, “Running Eagles Plan To Air It Out Versus Rams” (AP) , pg. P-6, col. 4:
“Prevent defense prevents you from winning,” he said.
(Philadelphia Eagles coach Buddy Ryan—ed.)

Covers
September 9, 1997
The Prevent Defense in All its Glory
By LOU
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Somebody (I think it might have been Joe Theismann, unfortunately) once said, “The only thing the prevent defense will do is prevent you from winning.”

ESPN
January 16, 2009
In Defense Of The Prevent
John Madden threw it under the bus. We defend it.
by David Fleming
John Madden once famously quipped that “the only thing the prevent defense does is prevent you from winning.” But it’s high time commentators, fans and even players showed some love for this much-maligned scheme. It works—and we can prove it.

Google Books
The Complete Idiot’s Guide to Understanding Football
By Mike Beacom
New York, NY: Alpha Books
2010
Pg. 178:
The only thing the prevent defense does is prevent you from winning. —Legendary NFL coach and television analyst John Madden