Eight months ago, Yogi Ferrell went undrafted out of Indiana. For February, the NBA named him Western Conference Rookie of the Month. It’s the latest accomplishment in Ferrell’s meteoric rise, and it puts the Mavericks point guard in rare company. Since the NBA began awarding Rookies of the Month in 1981, only one — Grizzlies guard Tarence Kinsey (April 2007) — earned the honor in his first professional season after going undrafted. Kinsey signed with Memphis shortly after the 2006 draft and made the regular-season roster.