Holtmann signed a top 25 class last fall, but none of the four players in the group came as highly regarded as Bates-Diop, who was a top 30 prospect coming out of Normal, Illinois in the class of 2014.
Now Holtmann has two top 30 players committed for 2019, the latest being D.J. Carton.
A five-star point guard from Bettendorf, Iowa, Carton reportedly chose Ohio State over Indiana and Michigan.
He's the No. 2 point guard in the country and ranked the No. 21 overall prospect in the nation according to the 247Sports Composite rankings.
Carton joins Garfield Heights forward Alonzo Gaffney (who committed in April) to form the No. 4 recruiting class in the country at the moment.
Why Ohio State?
Carton told 247 it was a matter of his relationship with the current Buckeyes.
"I felt like I was already apart of the team. They brought me in. I feel like I can be myself around them. It came down to that. The other two schools had everything I liked, and it was a really hard decision, but it came down to that."
Carton and Gaffney can sign in November.
They are scheduled to join a roster that already looks pretty solid all around.
Though college basketball rosters are more fluid than ever, the 2019-20 Buckeyes should include a proven big man (Kaleb Wesson), a pair of four-star forwards (Kyle Young and Jaedon LeDee) and multiple young guards/wings, including Musa Jallow, Duane Washington, Luther Muhammad and high-scoring Versailles product Ahrens.
Ohio State also has CJ Walker, a transfer from Florida State who must sit out this season, at point guard, so Holtmann should have plenty of options when it comes to putting together lineups.