“A happy fighter is a dangerous fighter” (boxing adage)

“A happy fighter is a dangerous fighter” (or “The most dangerous fighter is a happy fighter”) is a boxing adage that is frequently credited to heavyweight champion Mike Tyson. Tyson mentioned the advantages of being a “happy fighter” in several interviews.
 
Mike Tyson said in the documentary film Tyson (2008):
 
“There’s nothing like fighting when you’re young and you’re happy. There’s nothing more deadly or more proficient then a happy fighter. Everybody believes the mean, and the surly fighter, is the tough fighter but that’s not true. The guy who’s most relax and loves what he does, and is happy to be in there doing what he does.”
 
   
Wikipedia: Mike Tyson
Michael Gerard “Mike” Tyson (/ˈtaɪsən/; born June 30, 1966) is an American former professional boxer.
 
He is a former undisputed heavyweight champion of the world and holds the record as the youngest boxer to win the WBC, WBA and IBF heavyweight titles at 20 years, 4 months, and 22 days old. Tyson won his first 19 professional bouts by knockout, 12 of them in the first round. He won the WBC title in 1986 after defeating Trevor Berbick by a TKO in the second round. In 1987, Tyson added the WBA and IBF titles after defeating James Smith and Tony Tucker. This made him the first heavyweight boxer to simultaneously hold the WBA, WBC and IBF titles, and the only heavyweight to successively unify them.
       
IMDb (The Internet Movie Database)
Tyson (2008)
Quotes
Mike Tyson: There’s nothing like fighting when you’re young and you’re happy. There’s nothing more deadly or more proficient then a happy fighter. Everybody believes the mean, and the surly fighter, is the tough fighter but that’s not true. The guy who’s most relax and loves what he does, and is happy to be in there doing what he does.
 
Boxing News (Russia)
David Tua-Shane Cameron is Agreed Upon For June 6
17 Jan 2009 21:48
“A happy athlete is a good athlete. A happy fighter is a dangerous fighter. My priority for the last year has been to make sure my relationship with my wife is where it needs to be and my relationship with my sons is where it needs to be. Knowing that side of it is great allows me to have the peace of mind to be able to put all my energies now into preparing for this fight. There’s nothing else for me to do now other than to concentrate on winning.”
(Heavyweight fighter David Tua.—ed.)
 
Twitter
Scott Semple
‏@scottsemple
“The most dangerous fighter is a happy fighter.”
- Mike Tyson
12:15 AM - 25 Aug 2009
   
McDaniel College (Westminster, MD)
Lax standout scores on family legacy
March 30, 2010
by Katherine Restrepo ’12
(...)
Gibbs often quotes Mike Tyson who said, “Nobody’s a more dangerous fighter than a happy fighter.”
 
Sherdog (Mixed Martial Arts)
STRIKEFORCE CHAMP RONDA ROUSEY PLEASED WITH PATIENCE, MATURITY IN SUBMITTING SARAH KAUFMAN
BY MIKE WHITMAN
AUG 19, 2012
(...)
Prior to tonight’s contest, Rousey notably supplemented her preparation by spending time with Team Cesar Gracie, a decision she says paid both physical and mental dividends.
 
“They did a lot in keeping me from plateauing. I feel like changing your environment is really important, in moderation, and they were great,” Rousey said. “They helped me stay motivated and helped me to still enjoy what I’m doing. I think Mike Tyson said that a happy fighter is a dangerous fighter. They were really good about teaching me a whole lot of new things but also making sure that I was enjoying the journey.”
 
Google Books
The Domino Diaries:
My Decade Boxing with Olympic Champions and Chasing Hemingway’s Ghost in the Last Days of Castro’s Cuba
By Brin-Jonathan Butler
New York, NY: Picador
2015
Pp. 24-25:
It might be true that boxing is one of the only places where people with prison records and otherwise rotten resumes don’t start at the bottom, but then again, nobody’s a more dangerous fighter than a happy fighter.
 
Twitter
Ronda Rousey
‏@RondaRousey
“A happy fighter is a dangerous fighter” on the double end the other day with @melsik_the_gun http://instagram.com/p/x_bGYqhET0/
3:54 AM - 18 Jan 2015
 
Facebook
Edvin Kibus shared Xplosion Fight Series’s photo.
May 8, 2015 · Edited ·
Mike Tyson: There’s nothing like fighting when you’re young and you’re happy. There’s nothing more proficient than a happy fighter. Everybody believes that the mean, and the serly fighter, is the tough fighter but that’s not true. The guy who’s most relaxed and loves what he does, and is happy to be in there doing what he does.
 
Western Morning News (UK)
Jamie Speight ready to take on ‘nervous’ opponent for English featherweight title
By Western Morning News |  Posted: September 04, 2015
By ANDY PHILLIPS
(...)
“I can still train at home and live at home, and it’s like the old saying ‘a happy fighter is a dangerous fighter’.”