Duckworth was born in Harvey, Illinois, and grew up in Chicago, where he played basketball at Thornridge High School.

[1] Duckworth was the ninth pick in the 2nd round of the 1986 NBA draft, chosen by the San Antonio Spurs.

Also, after having previously never averaged over 70.0 percent from the free throw line, he shot 77% that year, rebounded well, and played good defense – earning him the 1988 NBA Most Improved Player Award.

The following season, Duckworth improved his averages to 18.1 points and 8.0 rebounds, and was named to the Western Conference All-Star team.

Although 1988–89 was statistically Duckworth's best season, the team enjoyed greater success in the following years — advancing to the NBA Finals in 1990, and posting a 63–19 record in 1990–91.

The presence of Williams as the starting power forward, with rebounding as his main assignment, allowed Duckworth to concentrate on scoring and defense.

During the 1994–95 season, during which he was reported to weigh 310 lbs, he was suspended indefinitely for not staying in good physical condition.

Duckworth was in town as part of a Trail Blazers group hosting a free children's basketball clinic.