Mariano Duncan, a Dominican-born infielder on the New York Yankees, said in July 1996:
 
“We play today. We win today. Das it.”
 
The saying was printed on T-shirts and became a slogan of the 1996 New York Yankees team that would go on to win the World Series. Wade Boggs, a teammate of Duncan’s on that 1996 team, applied for a trademark of “WE PLAY TODAY. WE WIN TODAY. DASSIT!” on August 14, 1996.
 
 
Wikipedia: Mariano Duncan
Mariano Duncan Nalasco (born March 13, 1963 in San Pedro de Macoris, Dominican Republic) is a retired second baseman and shortstop who played for several Major League Baseball teams during his 12 year career. He was the infield coach and 1st base coach for the Los Angeles Dodgers under Managers Grady Little and Joe Torre. Mariano currently serves as the hitting coach for the Daytona Cubs, the Chicago Cubs’ Single A team.
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New York Yankees
On December 11, 1995, Duncan signed with the New York Yankees, and he spent a season and a half in New York. In his only full season in 1996, he hit .340 with 56 runs batted in.
 
Duncan coined the phrase, “we play today, we win today… das it!” which became the mantra for the 1996 World Series champion New York Yankees. Many of the players wore t-shirts with the slogan under their uniforms daily.
 
29 July 1996, Daily News (New York, NY), “Darryl’s It: Proves Willing, Able To Fill Yank Hero Role”:
“We play today, we win today!” shrieked Duncan. “Das-sit.” Strawberry smiled knowingly.
 
5 August 1996, Denver (CO) Post, “Joe Torre’s Yankees have turned it on to lead the A.L. East” by Jerry Crasnick, pg. D1:
Mariano Duncan, another National League refugee, recently showed up in the clubhouse with T-shirts bearing the slogan, “If We Play Today, We Win Today.”
 
Google Books
Champions!:
The Saga of the 1996 New York Yankees
By John Harper and Bob Klapisch
New York, NY: Villard
1996
Pg. 171:
In fact, it was Duncan who coined the phrase that became the team motto: “We play today, we win today . . . Dassit.” “Dassit” was supposed to mean “That’s it,” but Duncan wasn’t above laughing at his own thick Dominican accent. The credo represented the Yankees’ uncomplicated, selfless approach to baseball in the summer of ‘96. Play and win.
 
Depressed Fan
Oct 7 2007 2:45 AM
“We Play Today, We Win Today. Das It.”
The immortal words of Mariano Duncan before game 6 of the 1996 World Series. Perfect words for that day, and perfect words for today as well.
 
New York (NY) Times—Bats blog
May 30, 2008, 11:25 am
Torre Followed Orders While Quietly Getting His Players’ Backs
By JACK CURRY
Mariano Duncan played under Joe Torre for two years with the Yankees and is now Torre’s first base coach on the Los Angeles Dodgers. Duncan batted .340 in 1996 and helped the Yankees secure a World Series title. He also coined the phrase that the team wore on T-Shirts: “We play today, we win today. Dassit.”
 
New York (NY) Post
Yankees fans enjoying unexpected ride
By MIKE VACCARO
Last Updated: 4:58 AM, May 19, 2013
Posted: 1:10 AM, May 19, 2013
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“You know what I dug out of attic the other day?” a Yankees fan I know emailed not long ago. “Remember those old shirts from ’96, the ones they used to wear with, ‘We Play Today, We Win Today’ on them? I even wore it.”
 
(Trademark)
Word Mark WE PLAY TODAY. WE WIN TODAY. DASSIT!
Goods and Services (ABANDONED) IC 024. US 042 050. G & S: cloth pennants
(ABANDONED) IC 025. US 022 039. G & S: clothing, namely, T-shirts, hats, sweatshirts, shorts, sweaters, visors, headbands, sweat bands, pajamas, underwear and jogging suits
Mark Drawing Code (1) TYPED DRAWING
Serial Number 75149991
Filing Date August 14, 1996
Current Basis 1B
Original Filing Basis 1B
Published for Opposition June 17, 1997
Owner (APPLICANT) BOGGS, WADE ANTHONY INDIVIDUAL UNITED STATES c/o CSMG International, Inc. 790 Frontage Road Northfield ILLINOIS 60093
Attorney of Record MAX SHAFTAL
Type of Mark TRADEMARK
Register PRINCIPAL
Live/Dead Indicator DEAD
Abandonment Date January 30, 1998