Input (grade 13): She quit the sport amidst controversy in 1988 while at the height of her ability, due to a dispute over her conduct in a match at the World Open Nine-ball Championship of that year.
Output (grade 7): She quit the sport during a time of controversy in 1988 while at the very height of her ability. This was because of a dispute that happened in a match at the World Open Nine-ball Championship of that year.