“If a play is working, keep running it” is a sports adage used in football, but also in other sports such as basketball. If a football team can’t stop the run, for example, then the other team should keep running the ball. A team keeps doing what works.
 
It’s not known who first stated the adage. “You keep running it until it’s stopped” was cited in print in 1978. “When the play works, you keep running it” was said by Gerald Ford (the U.S. president and a former collegiate football player) in 1980. Ford called it “an old football adage.”
 
   
Google News Archive
9 October 1978, The Register-Guard (Eugene, OR), “Herrera connects when it counts most” (UPI), pg. 3B, col. 5:
“You run a play until the cows come home,” Seattle quarterback Jim Zorn said of Tarkenton. “You keep running it until it’s stopped. Wasn’t he (Tarkenton) fantastic?”
 
12 December 1980, Richmond (VA)

,  “Fit and Likable, But Maladroit” by Joseph Kraft, pg. A-7, col. 1:
“There is an old football adage,” he (Gerald Ford—ed.) says of his own prescription. “When the play works, you keep running it.”
 
SunSentinel (Fort Lauderdale, FL)
Music
February 5, 2000|Dallas Morning News
Live at Azusa 3: Reminding the Saints of the Hope
Carlton Pearson
Atlantic, 65 minutes
Football analysts often say that if a play works, keep running it until the other team stops it. That must be Bishop Carlton Pearson’s thinking, too, because he keeps coming back with winners with his “Live at Azusa” CDs. The latest is actually the fifth such recording.
   
Washington (DC) Post
Cavs Shake Off Funk, And Duke
Pearman’s Running Helps Team Overcome Slow Start: Virginia 37, Duke 16
By Mark Schlabach
Washington Post Staff Writer
Sunday, October 24, 2004; Page E13
(...)
“We knew we wanted to run the ball, and we got it rolling early,” Pearman said. “That’s what [offensive coordinator Ron] Prince likes to do. If a play is working, he’s going to keep running it.”
     
The Huffington Post
Miles Mogulescu (Entertainment attorney, writer and political activist)
Dems Must Play Smash Mouth Football on National Security: Are You Safer Now Than You Were 6 Years Ago?
Posted: 12/31/1969 7:00 pm EST Updated: 05/25/2011 12:00 pm EDT
It’s fall—the season for two all American blood-sports: Football and elections. There are many similarities.
 
One of the first rules of football is that if a play is working, keep ramming it down the other team’s throat until the defense consistently stops it. If your right-side offensive line is pushing the defense off the line, then keep running the ball hard to the right.
 
Google Books
Tales from the Indianapolis Colts Sideline:
A Collection of the Greatest Colts Stories Ever Told
By Mike Chappell and Phil Richards
New York, NY: Sports Publishing
2012
Pg. ?:
“If it works, keep running it. It was the same play both times,” said Harrison, who caught eight passes for 125 yards that December day in 1999.
 
Twitter
matt just-stein
‏@mattjustt
@niehoff_kevin if a play works and the other team can’t stop it than why would you not keep running it?
11:49 PM - 4 Oct 2014
 
Minnesota Public Radio
The NFL’s most important city doesn’t even have a team
Bob Collins January 9, 2015, 2:30 PM 13
There’s an old saying in sports: If a play is working, just keep running it.