Rosas, you see, is one of four lead decision makers for N.B.A. teams known to still do the bulk of their business on a BlackBerry. Rosas, Houston’s Daryl Morey, Oklahoma City’s Sam Presti and Toronto’s Masai Ujiri compose the confirmed quartet. Milt Newton, Milwaukee’s assistant general manager, is another Blackberry devotee. Perhaps more will become known after this article hits, but Rosas described the adherents as “a small community.”