The University of North Carolina, Chapel Hill, was the only school among the four No. 1 seeds in the NCAA men’s tournament to graduate at least 50 percent of its players.

A report released Monday found 86 percent of Tar Heels men’s players earned diplomas during a six-year period. The other top seeds were far worse: 45 percent at the University of Kansas; 40 percent at the University of California, Los Angeles, and the University of Memphis.

The study of most tournament-bound teams was conducted by Dr. Richard Lapchick, head of the University of Central Florida’s Institute for Diversity and Ethics in Sport. It evaluated four different freshman classes for a period beginning in 1997-98 and ending with 2000-01. Though the players evaluated are no longer on campus, the report intends to provide a snapshot of academic trends.

Lapchick’s primary concern was the disparity between Black and White players. Thirty-three schools graduated at least 70 percent of their White men’s basketball players; only 19 graduated that many Black players. At least 50 percent of White players earned degrees at 45 schools, but Black athletes had that much success at only 36 schools.

But the study found that the achievement gap was shrinking. At 34 percent of tournament-bound teams there was a 30-point or greater difference in graduation success between Black and White players, down from 49 percent last year. Black players continued to succeed at higher rates than Black nonathletes.

“Higher education’s greatest failure is the persistent gap between African-American and White basketball student-athletes in particular, and students in general,” Lapchick wrote. “The good news there is that the gaps are narrowing slightly.”

According to NCAA data, graduation rates for Black men’s basketball players have improved 14 percent overall since 1984.

“We’ve seen some real improvement over time,” NCAA spokesman Erik Christianson said. “There’s always room for more improvement, but we’re pleased with the progress.”