A 6-foot-9 forward with an accurate shooting touch, Cummings spent the most productive stretch of his 12-year career with the New York Knicks and the Dallas Mavericks of the National Basketball Association (NBA), averaging better than 12 points and eight rebounds for four straight seasons.

He led the team to a pair of District 6 Class A championships, including a 25–1 record his senior year.

Cummings still holds the Bearcats' single-season field goal percentage record (.642 in 1977–78) and his career mark of .581 is second to Kenyon Martin.

He did shine at times, with a then career-high 25 points on February 26, 1980, against the Los Angeles Clippers, then 30 in the third-to-last game of the season against the Denver Nuggets.

[6] Over the next three seasons, he saw limited action in a front court that included Bob Lanier, Dave Meyers, Marques Johnson, Kent Benson, and Harvey Catchings.

He spent two more seasons with the Knicks, sharing time in the front court with Bill Cartwright and Patrick Ewing.

He started in the Heat's first-ever game, and spent most of his two years in Miami as a backup to Rony Seikaly.

On Dec. 14, 1988, Cummings scored 15 points to help lead the Heat past the Los Angeles Clippers, 89–88, for their first victory, after they opened the season with a then-N.B.A.

[15] In a 2016 interview, Cummings' former teammate Bernard King remarked "We've lost a lot of guys over the last couple of years.