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Before it became a rallying cry for enthusiastic college basketball student sections or hopeful U.S. soccer fans, the trendiest chant in American sports began as something much less grandiose.

It was the brainchild of a Naval Academy Prep School student who never expected it to spread across his own campus, let alone across the nation.

Tasked with inventing a cheer for his 50-member platoon in fall 1998, Jay Rodriguez conceived of the now-famous "I believe that we will win" chant and taught it to his peers. Classmates say it was such an instant hit that members of other platoons joined in the rest of the school year whenever Rodriguez led the chant at Navy Prep basketball and football games.

"The first time we heard it, we all thought, 'This is awesome,'" said John Reeves, who attended Navy Prep and the Naval Academy with Rodriguez. "Jay was really good at coming up with stuff like that because he was very intelligent and very creative. It caught on like wildfire."

To the bewilderment and amusement of those who know its humble origin, "I believe that we will win" has steadily gained popularity the past 15 years, evolving from a platoon chant, to a Navy football tradition, to a staple of sporting events nationwide.

It started with Rodriguez's Navy Prep class bringing the chant to the Naval Academy and teaching it to the rest of the brigade. Over the next decade, students at other high schools and colleges caught glimpses of 4,000 Midshipmen jumping up and down in the bleachers performing the chant and introduced versions of it at their own basketball and football games. By 2010, rooting sections for several Major League Soccer franchises decided to borrow the chant after noticing the fun that fans at schools like Utah State and San Diego State were having performing it before games.

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The fervor for the chant has reached new levels in recent months as it has become the anthem for the U.S. soccer team. In the build-up to the World Cup, ESPN unveiled a series of "I believe that we will win" commercials, the first showing footage of thousands of red-white-and-blue-clad American fans performing the chant and the second with celebrities like Kevin Costner, Ice Cube and Barry Sanders doing it.

"The first time I heard the "I believe" chant for a U.S. game was in Kansas City [in 2011]," said Justin Brunken, co-founder of the U.S. soccer support group known as the American Outlaws. "It was a chant that just grew from there and caught on and on. It resonated with the crowds across the country and became synonymous with what we believe in and became the battle cry for this World Cup."

"I believe that we will win" might never have spread had Rodriguez not taught the chant to classmate Corey Strong early in their plebe year at the Naval Academy. Strong, a cheerleader, grabbed a microphone and led the entire brigade in the cheer during the fourth quarter of the 1999 Army-Navy football game as the Midshipmen were finishing off a 19-9 victory over the rival Cadets.

View photos San Diego State fans do the chant before every home basketball game. (USA TODAY Sports) More

When Strong bellowed "I" into the microphone, the rest of the brigade shouted it back at him. When Strong followed that by screaming "I believe," the brigade once again responded in kind. Pretty soon 4,000 Midshipmen were jumping up and down in uniform in the bleachers pumping their fists and yelling "I believe that we will win" in unison over and over.

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