Has a College Football game ever ended 15-11?
It has. 15-11 has been a College Football final 6 times in 84,334 games. The first was Wesleyan (CT) beat Amherst on November 23, 1901; the latest was Kentucky beat Vanderbilt on November 11, 1989.
That makes 15-11 the 1222nd most common final score out of 2,215 that have ever occurred in College Football. One point away, 16-11 has happened 9 times and 15-12 has happened 35 times. At one point the score disappeared for 68 years, between 1907 and 1975.