In the 1993–94 NCAA season, Coach Dave Odom was considering redshirting Duncan, but was forced to play him after fellow freshman big man Makhtar N'Diaye was ruled out due to NCAA rules violations and eventually transferred to Michigan.
Duncan struggled with early transition problems and was even held scoreless in his first college game, but as the year progressed, he and teammate Randolph Childress led the Deacons to a 20–11 win-loss record.
Overall, Duncan led his team to a 97–31 win–loss record and finished his college career as the all-time leading rebounder in NCAA history in the post-1973 era (later surpassed by Kenneth Faried).
He remains one of only ten players with more than 2,000 career points and 1,500 career rebounds.
In contrast to contemporary prep-to-pro players like Kevin Garnett, Jermaine O'Neal, Tracy Mc Grady or Kobe Bryant, Duncan stayed at college for a full four years.
During that period, he was a two-time ACC Player of the Year, and a three-time NABC Defensive Player of the Year.
This provided an opportunity for Duncan to show his leadership qualities, and his inexperienced team lost only four games in the entire ACC season.
The Demon Deacons won the ACC Finals again, but in the Sweet 16, Duncan came down with the flu, and his team missed the Final Four by one win.
So big and tall, but he was awfully awkward at the time." He overcame this to become a standout for the St.
Dunstan's Episcopal High School, averaging 25 points per game as a senior.
He was giving up a lot of money, but was determined to stay in school.
In that season, he led the Demon Deacons into the Atlantic Coast Conference (ACC) championship game against a Rasheed Wallace-led North Carolina Tar Heels.
Duncan is the only son of Ione Duncan, a midwife, and William Duncan, a mason, and has two older sisters, Cheryl and Tricia.